Battery light flickering?

[jawn101]

Hey all. Just finished up a VOD maintenance cycle, and while I was running the engine to bleed coolant and go for the maiden voyage today, I noticed the battery light in the dash is dimly flickering. I topped off the battery overnight last night and again on a quick charge this morning, it was reading 100% and 13.2 volts on my charger. The voltmeter in the car reads a nice steady 13-14ish when the engine is running, the alternator is spinning (and brand new from Hervey) and I double and triple-checked the connections to the alt and battery itself.

Everything looks OK to me. The battery light wasn't doing this before we tore down the engine. The only thing I can think of is that when we topped off the coolant, some spilled out the overflow hose on the bottle and may have gotten on the alternator. I didn't see that for certain but it's certainly possible.

Any ideas what to look for or what to do?

[Michael]

Could be a number of things, bad ground, bad alternator, loose connection on the alternator, but the very first thing I would suspect is a slipping belt, even if its tight, look at the belt surface and see if its glazed over. If so replace and/or tension properly. Also check your battery terminal connections.

Ps if your belt is slipping, the volt gauge may not react quick enough for you to see the dip. Try driving with the ac and headlights on, this will put more strain on the alternator so when the belt slips, the volt gauge will fluctuate more and you will have it narrowed down to the belt being the culprit.

[Bitsyncmaster]

As long as the volt gauge looks good your probably OK to run it that way. Maybe the electronics turning the light on if voltage looks low is bad. In either case if it continues you probably want it fixed. Is your alternator still under warranty?

[jawn101]

As long as the volt gauge looks good your probably OK to run it that way. Maybe the electronics turning the light on if voltage looks low is bad. In either case if it continues you probably want it fixed. Is your alternator still under warranty?

It might or might not be. I had it repaired by Hervey once already, it burned up due to a loose connection (which is why the first thing I checked was the connections) so the warranty may be moot.

I will check if the belt is slipping, it does feel like it deflects a little more than I remember before we tore it down. The belts themselves are brand spankin' new, but the tension could be an issue.

[jawn101]

Could be a number of things, bad ground, bad alternator, loose connection on the alternator, but the very first thing I would suspect is a slipping belt, even if its tight, look at the belt surface and see if its glazed over. If so replace and/or tension properly. Also check your battery terminal connections.

Ps if your belt is slipping, the volt gauge may not react quick enough for you to see the dip. Try driving with the ac and headlights on, this will put more strain on the alternator so when the belt slips, the volt gauge will fluctuate more and you will have it narrowed down to the belt being the culprit.

I got under the car and re-tightened the belt (was part of my shakedown plans anyway) and it was definitely not as tight as it could have been. Not *loose* but not perfect either. After tightening, I ran the engine for a few more minutes (part 4 of the great coolant bleed, lol) and didn't notice the battery light flickering. Guess that was it! Thanks for the tip.

[DeLorean03]

Keep your eye on this problem. Mine started about 1 year ago. The light flickered more and more and more until it started getting near a constant "on" condition. Was on the interstate driving home and my voltmeter plunged. I pulled over and check the brown wire with a female ended plug that goes to the top left of the alternator all by itself. That was the problem. I disconnected the plug and took it inside. I unwrapped the electrical tape that housed the plug. In that plug was a 1 MOhm resistor (unknown power rating). One end was still connected firmly to the female end of the plug. The other..... the soldering join was "giving up the ghost" - and that was causing my battery light to flicker more and more and more and more as time went along.

Just one of those "things I found" and wanted to put it up here as "possible reasons" for battery light flickering.

[jawn101]

Keep your eye on this problem. Mine started about 1 year ago. The light flickered more and more and more until it started getting near a constant "on" condition. Was on the interstate driving home and my voltmeter plunged. I pulled over and check the brown wire with a female ended plug that goes to the top left of the alternator all by itself. That was the problem. I disconnected the plug and took it inside. I unwrapped the electrical tape that housed the plug. In that plug was a 1 MOhm resistor (unknown power rating). One end was still connected firmly to the female end of the plug. The other..... the soldering join was "giving up the ghost" - and that was causing my battery light to flicker more and more and more and more as time went along.

Just one of those "things I found" and wanted to put it up here as "possible reasons" for battery light flickering.

Roger that - I believe that is the regulator circuit and it would definitely play a role. Mine is a brand new connection (less than 3 weeks old) and was fine previously; but I checked it all the same. Looks good right now but definitely a thought to keep in the back pocket, with a spare roll of electrical tape... :)

[DMC3165]

Which alternator are you running? I've heard a few of the high output ones tend to wreak havoc with the battery light. I am currently running a Hervey 90 amp and have had zero trouble with it since last November. Even now in the 100 degree heat with the A/C on full blast and my coolant fans churning up a typhoon the voltage drop at a light is noticeable but no danger of stalling even at night with the lights on.

[jawn101]

Which alternator are you running? I've heard a few of the high output ones tend to wreak havoc with the battery light. I am currently running a Hervey 90 amp and have had zero trouble with it since last November. Even now in the 100 degree heat with the A/C on full blast and my coolant fans churning up a typhoon the voltage drop at a light is noticeable but no danger of stalling even at night with the lights on.

I got the 110/120A one. It's actually great, plenty of power and no issues... but the belt was loose for sure.

[uhhair]

On our car, we had an older alternator that was not meant for the Delorean, and the output of the alternator was a little lower than it should have been. As a result, the volt gauge read slightly below what it should, and our battery light was always on, but VERY dim, you could only see it was illuminated at night. We had a host of other gauge issues with the console so we didn't know at the time what the issue was with the alternator, since the car never died or failed to run anything properly, but this turned out to be the issue. I'd check the alternator and make sure everything with it is a-ok.

[jawn101]

Ok, so this is still happening (sort of) - I think I need to understand the function of the battery light better to diagnose the issue. Now what I am seeing is one or two flashes of the light at high RPM, just before an upshift. In my little mind, that means that my battery is actually failing since at high RPM the alt would be outputting it's max power, and the battery, if low on voltage, would imbalance that circuit and cause the lamp to glow. Am I way off base there?

When I pull my battery off and put it on my conditioner, it usually reads 12.6 volts and "85%" - the takes about 5 minutes on a 15A charge cycle to read 13.2 volts and "100%". The battery is fairly new but of unknown age ultimately. Came with the car when I got it in March and has no date of mfg on it.

[Rich]

Ok, so this is still happening (sort of) - I think I need to understand the function of the battery light better to diagnose the issue. Now what I am seeing is one or two flashes of the light at high RPM, just before an upshift.

Understanding the battery light on the inst. panel - From the DMC Technical Info. Manual, p.32: "Whenever the ignition switch is in the "run" position and the alternator is not producing voltage, the voltage regulator will allow current to flow through the indicator bulb circuit, lighting the lamp. Any voltage produced by the alternator, above that of the battery, will cause the voltage regulator to turn the indicator lamp off."

From this and an assumption that the voltage regulator is behaving itself the diagnosis is that the alternator system is not delivering voltage under some conditions.

Yes, unusual if the lamp flickers at high engine speed. Could the drive belt be slipping due to high centrifugal force? Check belt condition (not glazed?) and tension.

Other culprits include intermittent open in wiring/connectors including grounds, bad alternator. You already know not to replace the battery lamp with an LED.

You do see the battery lamp lit with the engine off and ignition "ON", right? To drill down further you could rig a VOM to a good positive and ground, tape it to the binnacle, then go for a drive, comparing voltage readings to lamp-flicker events.

[Michael]

Ok, so this is still happening (sort of) - I think I need to understand the function of the battery light better to diagnose the issue. Now what I am seeing is one or two flashes of the light at high RPM, just before an upshift. In my little mind, that means that my battery is actually failing since at high RPM the alt would be outputting it's max power, and the battery, if low on voltage, would imbalance that circuit and cause the lamp to glow. Am I way off base there?

When I pull my battery off and put it on my conditioner, it usually reads 12.6 volts and "85%" - the takes about 5 minutes on a 15A charge cycle to read 13.2 volts and "100%". The battery is fairly new but of unknown age ultimately. Came with the car when I got it in March and has no date of mfg on it.

That really sounds like a slipping belt. Can you post a good close-up pic of your alternator pulley with the belt on it?

I had a Special T alternator on my car for a long time, and it took me forever to trace this problem down, but here is what happened. About 2 years ago, I put a Special T alternator on my car, worked fine for a long time. Late last year, my battery light flickered too and mainly only at interstate speeds or heavy acceleration, especially at night or when the AC was on(which demanded more from the alternator). In the daytime, with ac off, it would ONLY happen upon heavy acceleration right before an upshift. I quickly realized this was a slipping belt, but after 2 belts the problem was still there. I finally bought a DMC belt from DMCMW thinking the aftermarket belts were not making enough contact with the pulley. I even sanded the pulley trying to give it more bite. After installing the DMC belt, I was just looking at my alternator and it dawned upon me, the pulley was too narrow. The DMC belt was much wider and was riding well above the groove. It's supposed to ride a little above the groove(about 1/8 inch, but not this much) I then ordered a DMC alternator and it's been smooth sailing ever since.

Post a picture of the installed and tensioned belt on the pulley, maybe post more the one so we can see how it's seated in the pulley and lets go from there.

[Bitsyncmaster]

You can not use a DMC belt on John's alternators. His pulley is smaller and the belt has to be shorter. It may also be the pulley center line is shorter than the OEM alternators which also would require a shorter belt

[David T]

If the charging light is flickering do the following:

Load test the battery. If it is over 5 years old just replace it
Output test the alternator. Many auto stores will test the battery and alternator for free in the hopes of selling you new ones.
Check the tension of the belt. Make sure it is not riding on the bottom of the pulleys, only the sides of the "Vee" should ever touch the pulleys
Ultimately you will probably be replacing the alternator and maybe the battery. The other possibility is a bad electrical connection. Rare but possible.
David Teitelbaum

[jawn101]

OK, so here's what I've found in response to everyone's questions (thanks all by the way)

- I am using the Special T alternator with a brand new water pump and the Special T alt belt that came with the alternator
- The belt doesn't appear to be glazed or loose, I can't turn anything by hand and it deflects approximately the right amount, at least by feel anyway
- The battery light does illuminate when the key is 'on' but the engine is not running. The lamp is not an LED
- The alternator is brand new but was damaged and repaired by John.
- Here are some pictures of the pulley/belt interface

2885
2886
2887
2888
2889
2890
2891

[DeLorean03]

I just walked outside and checked mine since we both have John alternators with belts.

Your belt looks great. I honestly don't see any indicators that your belt is wrong or faulty. Maybe just tighten it down a lil bit more? By use of a pry-bar and some patience, you can do it as a one man job.

[Rich]

+1 on prev. post.

A static pulley-turn test is not always enough to diagnose this. Haul down on the tension a few more clicks, only for test purposes to rule the alternator drive system out. Test-drive it. If the flickering gets better then you've keyed into a cause. If no change then it's not the belt.

Another trick is to back off on the tension a bit and see if the problem's worse. If you can turn the symptom on and off with tension then you are close to a solution.

Put the tension back where you like it after the test(s).

More about the belt later, depending on how this test goes.

[jawn101]

+1 on prev. post.

A static pulley-turn test is not always enough to diagnose this. Haul down on the tension a few more clicks, only for test purposes to rule the alternator drive system out. Test-drive it. If the flickering gets better then you've keyed into a cause. If no change then it's not the belt.

Another trick is to back off on the tension a bit and see if the problem's worse. If you can turn the symptom on and off with tension then you are close to a solution.

Put the tension back where you like it after the test(s).

More about the belt later, depending on how this test goes.

OK, so I just went and tightened the alt as far as it can possibly go given the lower mounting bracket. It didn't add much if any tension over where it already was, if I'm completely honest. Then I got on the highway - the battery light didn't come on at all at regular surface street speeds on the way to the on ramp, but then when I spin up to about 4500 in 2nd and 3rd, there it was. It's much tougher to see in the daylight than at night, since the flashes are pretty brief. The voltmeter is nice and steady about 5 or 6 degrees above the 13 mark. I did the test without any accessories running. The car runs and idles smooth as anything.

Once the exhaust manifold cools down I'm going to go check the single-wire regulator connection at the alternator - it hooks up with a 3M strip connector that I wrapped in electrical tape in with the B+ bundle. I guess it's possible it got loose somehow but I'm not sure.

What's next?

[DeLorean03]

Forgive me for asking, but you did loosen the 13mm bolt that connects the alternator to the rest of the engine and allows the alternator itself to swivel right? If you don't, you can tighten that belt all you want but it won't make a difference. You have to loosen the alternator so it can loosely swivel as you tighten the belt. Then you tighten down both the alternator and the belt.

Not trying to give you a hard time, just making sure everything's been down here before we move on.

[jawn101]

Forgive me for asking, but you did loosen the 13mm bolt that connects the alternator to the rest of the engine and allows the alternator itself to swivel right? If you don't, you can tighten that belt all you want but it won't make a difference. You have to loosen the alternator so it can loosely swivel as you tighten the belt. Then you tighten down both the alternator and the belt.

Not trying to give you a hard time, just making sure everything's been down here before we move on.

No worries. Yes, (and it's a 17mm that hangs the alt from the block) I loosen that, crank the alt all the way to the passenger's side, tighten down the nut on the adjustment bracket, then re-tighten the 17mm at the block. Then I re-tighten both again just to be sure. Because the lower bracket bolt is going through a threaded portion in the alternator body, it makes it really easy to torque the belt with two long 13mm wrenches turning in opposite directions.

[DeLorean03]

... it makes it really easy to torque the belt with two long 13mm wrenches turning in opposite directions.

Yep - totally agree. Ok, well you nailed that part - now we moved onto possibly a bad alternator or battery. Both easy to take off the car and test at Autozone. Say they're for ANYTHING else then a DeLorean - or they'll tell you it's for a damned rocketship.

For checking the alternator circuit:

http://dmctalk.org/attachment.php?attachmentid=81&d=1306264442

Maybe replace fuse #5 and make sure the connections going to the fuse box are all right?

At that point, I'd be taking my alt and batt to Autozone.

I trust John's work, but that line about "Broken alternator but John fixed it." would be in the back of my head.

[jawn101]

Yep - totally agree. Ok, well you nailed that part - now we moved onto possibly a bad alternator or battery. Both easy to take off the car and test at Autozone. Say they're for ANYTHING else then a DeLorean - or they'll tell you it's for a damned rocketship.

Would it be easier or better (to get the 'real world' spin factored in) to have them tested while still on the car? I know at my autozone, they have a handheld tester that can do certain things (although they are super-secret about telling me what)

[DeLorean03]

Would it be easier or better (to get the 'real world' spin factored in) to have them tested while still on the car? I know at my autozone, they have a handheld tester that can do certain things (although they are super-secret about telling me what)

For the battery, no. They have testers in 30 seconds that will nail the problem.

For the alternator, you'd have the load of the car being tested, but I would assume their testers could nail the problem just as well if you brought it in by hand. If it were me and I wanted to know for sure, yeah, I'd drive it in - take the battery out and tested - re-install if good or replace if bad battery - then have the alt tested while on the car.

So, battery - no. Alternator - yes. I'd drive my car up there and get both tested. Battery off the car - alternator on the car.

[jawn101]

For the battery, no. They have testers in 30 seconds that will nail the problem.

For the alternator, you'd have the load of the car being tested, but I would assume their testers could nail the problem just as well if you brought it in by hand. If it were me and I wanted to know for sure, yeah, I'd drive it in - take the battery out and tested - re-install if good or replace if bad battery - then have the alt tested while on the car.

So, battery - no. Alternator - yes. I'd drive my car up there and get both tested. Battery off the car - alternator on the car.

The Kragen and CarQuest by my house both say they need both parts off to do a bench test. AutoZone did test both for me a few months ago and informed me that my battery was OK but the alternator was shot - which confirmed what I had thought at the time, and I replaced the alt. I will go have them take another crack at it.

[DeLorean03]

The Kragen and CarQuest by my house both say they need both parts off to do a bench test. AutoZone did test both for me a few months ago and informed me that my battery was OK but the alternator was shot - which confirmed what I had thought at the time, and I replaced the alt. I will go have them take another crack at it.


In that case, I'd take both off and have both Kragen and CarQ test them. If both yield same results, those results are more than likely accurate and true. If one says good and another says bad, then I'd use Autozone as the deciding factor.

Alot of "trial and error" I know, but to nail this problem it's worth it.

[jawn101]

Another idea, I have Hervey's new upgraded ground cables but I haven't yet installed them. Some folks have mentioned grounds as the possible root cause here; I have cleaned nearly all of my ground connections except the main frame ground in the engine bay as I planned to replace it anyway. Should I do that before I go blaming the alternator? Normally I'd say it didn't make a huge amount of sense as the system seems OK at low RPM, but with the electrical system in this car, anything is possible...

[Michael]

OK, so I just went and tightened the alt as far as it can possibly go given the lower mounting bracket. It didn't add much if any tension over where it already was, if I'm completely honest. Then I got on the highway - the battery light didn't come on at all at regular surface street speeds on the way to the on ramp, but then when I spin up to about 4500 in 2nd and 3rd, there it was. It's much tougher to see in the daylight than at night, since the flashes are pretty brief. The voltmeter is nice and steady about 5 or 6 degrees above the 13 mark. I did the test without any accessories running. The car runs and idles smooth as anything.

Once the exhaust manifold cools down I'm going to go check the single-wire regulator connection at the alternator - it hooks up with a 3M strip connector that I wrapped in electrical tape in with the B+ bundle. I guess it's possible it got loose somehow but I'm not sure.

What's next?

Don't change a thing, do the same drive with the AC on and/or headlights on, if the problem is more pronounced, then you know the belt is slipping, and no further diagnosis is necessary. Also, be careful not to over-tighten the belt, it should have some movement(say an inch or less of side to side movement). In case you haven't guessed already, I still think your belt is slipping

[jawn101]

I just got home from doing as Delorean03 suggested and having the alt and battery load tested at the shop. Both tested perfectly fine. I came home and before reinstalling everything to do some more diagnosis, I cut open the bundle of wires to the alt and found the regulator connection, joined to the factory harness with a Scotch-Lok connector. Cut the connector out and re-spliced it with a stronger butt joint connection, put everything back together - voila! In the exact same test situation (no accessories, to the highway and on for a mile at 75mph) the light didn't flicker one time. So, on the return trip, I turned on the A/C (by this time I was sweating bullets anyway) and drove home - still nothing! Volt gauge is steady at 13+, no flicker in the warning light. Belt seems nice and tight (but I will snug it again tomorrow just to be sure)

I guess since the only real change was re-splicing the wire to the regulator that it must have been the issue? The only other thing I can think of is that the ground connection between the alt and the block was dirty and that the R&R helped clean it up.

Still something I'll keep an eye on for the next few weeks, but it looks like we got it. Thanks guys! There were a lot of great suggestions and posts in this thread so I hope it's one people refer back to some day.

[Michael]

Great news, a certan sense of pride and accomplishment should be upon you.

I would guess you had a dirty wire end on the back of the alternator and you re-positioned it a little when you R+R the alternator, might be a good idea to remove those wires again and take some sandpaper to the eye connectors.

[jawn101]

Great news, a certan sense of pride and accomplishment should be upon you.

I would guess you had a dirty wire end on the back of the alternator and you re-positioned it a little when you R+R the alternator, might be a good idea to remove those wires again and take some sandpaper to the eye connectors.

I am definitely pleased with the outcome. I don't think the ring terminals are a problem as I polished them mightily with a wire wheel when I first put this alternator on and they gleam like the sun. More likely it was that terrible Scotch-lok connector to the regulator circuit :)

Thanks again!

[jawn101]

Sigh. Just took a longer trip (about 20 miles) and I got a few brief flickers. They coincided with a lot of jitter in the tach (jumping to 4,5,6k rpm) and temporary reductions in blower fan speed (this was all with the AC on max and the stereo going). I know the dash grounds still need to be cleaned... But I guess I'm back to the drawing board.

[DeLorean03]

I cut open the bundle of wires to the alt and found the regulator connection, joined to the factory harness with a Scotch-Lok connector.

I'm still learning, so I just want to ask: what color is this wire? I tried to picture in my head what you described, but I couldn't think of how this setup looked. What color was this wire? Thank you, sir.

[jawn101]

I'm still learning, so I just want to ask: what color is this wire? I tried to picture in my head what you described, but I couldn't think of how this setup looked. What color was this wire? Thank you, sir.

Brown with a yellow stripe. Sir? :) no one's ever called me that without adding 'you're making a scene' before :)

[jawn101]

OK, so in an attempt to nail down this problem even further, I just went and installed the new Hervey ground wires I bought a while back. It's such a straightforward job, as many of you know - remove the battery, unbolt the ground cable from the passenger side trailing arm bracket, pull the wire through. Then run the new cable from the battery to the transmission, and the shorter cable from the transmission to the trailing arm bracket. Took about an hour and only because my little jack doesn't give me much room to work.

I had the battery on my conditioner while I did the work, on a top-off cycle. It was at capacity when I finished.

Let the car down, put the battery back and cranked the engine. Immediately I noticed that as John had promised, the car turned over like it was brand new. About a microsecond of starter crank and then immediate, perfect, smooth idle. Only problem now: the volt meter is reading sub-13 volts, where it was well over before I replaced the ground - more like 14.5

Curious, I blipped the throttle a few times - and the engine is falling all over itself. No acceleration. Everything was perfectly fine this morning before I changed the cable (with the exception of the flickering batt light at high rpm of course)

I did clean the bolts and washers that hold the ground cable to the frame and transmission. I also cleaned the trailing arm bracket where the ground cable makes contact with it. I used dielectric grease on both junctions - ground to frame and ground to transmission.

What's going on here?

Edit: Here's a quick iphone video of the problem. You may need the sound turned up loud to hear the issues with the engine running when I am throttling at the end. Click Me (http://reactorleak.net/pics/IMG_0637.MOV)

[Rich]

I used dielectric grease on both junctions - ground to frame and ground to transmission.

What's going on here?


First, when did you put the DE grease on the grounding junctions and did you apply it between the surfaces you want to carry current? DE grease is an insulator, is meant to go over the junction after it has been cleanly assembled. Not within the junction anywhere. Fix/clean it if in doubt.

Second, the newly-lower voltage is consistent with hesitation or rough running (low fuel pressure keeps injectors from opening fully).

So, in order: Good grounds first, then known-good battery (via off-car load test if need be), then good alternator/wiring.

[DeLorean03]

DE grease is an insulator, is meant to go over the junction after it has been cleanly assembled. Not within the junction anywhere. Fix/clean it if in doubt.


Wow, thank you for pointing this out. I have been doing it wrong too :smashfreak: - for 7 YEARS. Sheesh. Good to see I too just learned something that may be obvious to everyone else. Looks like I'll be cleaning all my connections as I get to them :wrenchin:

[DMC3165]

I'm just curious about one thing. In using DE, I thought it was ok to coat the contact surfaces with it before tightening the contacts. In theory this would protect any exposed areas from corrosion and whatever wasn't needed would simply be pushed out of the way as the surfaces made contact.

If not I've been using it wrong as well.

[jawn101]

I'm just curious about one thing. In using DE, I thought it was ok to coat the contact surfaces with it before tightening the contacts. In theory this would protect any exposed areas from corrosion and whatever wasn't needed would simply be pushed out of the way as the surfaces made contact.

If not I've been using it wrong as well.

+1 on that in a big way. That's exactly the principle I used - a thin coating on the components, then tighten them down and let the grease push out of the way. Maybe I used too much and will definitely revisit the connections this evening to check.

[DeLorean03]

What rwip said is pretty much dead on. After reading this, I did a little homework on DE, and found out it is an insulator. Basically, you want to get your connection totally clean and put it back together. Then, once the connection is put together, you want to put DE around that connection - so the DE is keeping water, air, humidity, etc from getting to the connection at all.

[jawn101]

What rwip said is pretty much dead on. After reading this, I did a little homework on DE, and found out it is an insulator. Basically, you want to get your connection totally clean and put it back together. Then, once the connection is put together, you want to put DE around that connection - so the DE is keeping water, air, humidity, etc from getting to the connection at all.

Well then, today has been a learning experience for sure :) I will tear the cables back down and clean the grease off tonight, then re-do it and report back.

[Rich]

More here about what DE Grease is and is not useful for:
Click and scroll down to Dielectric Grease (http://en.wikipedia.org/wiki/Dielectric_grease#Dielectric_grease)

Since it's an insulator it will not enhance a given 12V connection. DE grease (a.k.a. silicone grease) has its uses. This is not one of them.

Depending on the current flow and how well the connectors are mated you may get such pre-greased connections to work fine. It's not designed to help the initial connection. During repair and troubleshooting you want any possible hindrances like this out of the way or bypassed.

So after the DE grease is off your new grounds you may not be any better off but you'll not be any worse off, either. PS, if you greased the alternator (+) wires then give them a scrub, too.

During cleanup be sure to keep any silicone-based product like this off of the D's stainless (via your hands, rags). It's hard to get it off s.steel completely.

[jawn101]

As promised, here's my findings from this evening's work.

- Removed the battery again and put it on the conditioner
- Removed the new ground cables from the frame and transmission
- Cleaned the bolts, nuts, washers, frame, transmission and cables scrupulously
- Reinstalled the ground cables
- Reinstalled the battery

Turned the key to 'on' and - NO BATTERY LIGHT! I know it works, because the piece of crap wouldn't stop flashing at me all weekend... lol. I checked the #5 fuse and it's intact and connection is good. So I guess that means the regulator or the connection to it is acting up. The car still turns over beautifully, so the ground is good - and the voltage is higher than before, but without the alternator exciting and charging, it only went to about 13 (the battery read 12.88 on a DVM)

So I guess it all comes down to that alternator, time and time again. The voltage drops, the lack of excitement on the regulator circuit, it all really points to one place. I guess I need to call John tomorrow. Is there anything else I should try so I have all my ducks in a row?

[jawn101]

OK, one last question since I know people are sick of this thread already :)

John and I confirmed that the regulator is blown in the alternator. Must have happened when I took it in to be load tested - I made sure to tell the guy that it was a special hookup and didn't need to have voltage rammed into it, but I guess he must have anyway. My own fault for not paying close enough attention.

But that still leaves me the flickering light at high speed. I agree with pretty much everyone that the problem is that the belt isn't tight enough, but I'm using the correct belt from John for the smaller pulley, and the alternator is tensioned all the way to the end of the bracket. My original (or at least what was on the car when I got it) was the Ducy.

Looking at DMCH's site, I see two different tension brackets, one for the Ducy (https://www.delorean.com/store/p-6788-belt-tens-reg-brkt.aspx) and one for the Motorola (https://www.delorean.com/store/p-6810-bkt-belt-tens-reg.aspx)

Does anyone know the difference between these? Could I have the wrong one somehow? Does one allow for more tension than the other?

[Bitsyncmaster]

My car had the Ducy alternator and I installed John's 110 amp alternator with his belt. I did not have to tension it all the way to the end of the bracket

[jawn101]

My car had the Ducy alternator and I installed John's 110 amp alternator with his belt. I did not have to tension it all the way to the end of the bracket

Do you by any chance have the model # off the belt you're using? I'm just curious if I got these mixed up in my garage or something. Mine is 10AV1260

[Bitsyncmaster]

Do you by any chance have the model # off the belt you're using? I'm just curious if I got these mixed up in my garage or something. Mine is 10AV1260

I will look when I get home (if it still shows).

[DeLorean03]

Do you by any chance have the model # off the belt you're using? I'm just curious if I got these mixed up in my garage or something. Mine is 10AV1260

If it helps, here are the numbers off of my belt:

15495 <- -> 11AV1255

What I typed above is exactly what I see on the belt...1st numbers, then arrows pointing opposite directions, then the 2nd 8 digits of letters and numbers.

Been running John's D140 for 7 years now.

[jawn101]

If it helps, here are the numbers off of my belt:

15495 <- -> 11AV1255

What I typed above is exactly what I see on the belt...1st numbers, then arrows pointing opposite directions, then the 2nd 8 digits of letters and numbers.

Been running John's D140 for 7 years now.

Very interesting. I wonder if I have the wrong belt.

[Bitsyncmaster]

Here are photos of my belt and bracket.

[jawn101]

Here are photos of my belt and bracket.

Oh, really interesting. So you have a *490 belt as well, which John says is the correct one. DeLorean03 up there has the "wrong" belt on - his ends in 95, which means it's technically too long for the smaller Special T pulley. But, I can't criticize since I'm the one with the problem :)

What I do notice is that your tension bracket is mounted inversely to mine - with the fixed end bolted to the alt and the adjustable end on the block. That might be worth a shot. Thanks for getting those pics for me, Dave.

EDIT: Delorean03 has the 140amp, so maybe that uses a different belt than my 110? I don't know that for sure.

[Regulus]

Hello Everyone,

Apologies for resurrecting a dead link, but I think I have some further info to add on the flickering Battery Light. Long story short; I've had an issues with my A/C compressor going on 3 years now. Everything the A/C clutch disengaged, my Batt light came on for a second. This is a voltage spike, which I originally though was a bad ground/bad alternator/Bad Compressor. I eliminated all of those, and still have the problem. Another member used a diode and capacitor on the A/C Compressor wire, and that seemed to help. However, I finally got around to installing Toby's Fan Relay Upgrade, and that was solved 80% of the problem, plus made the alternator work much better (no draw down of voltage when fans are engaged, and much strong charging throughout.) I believe that the inherent problem was that when the A/C compressor clutch cycled off, thus turning the fans off, this cause the voltage demand to suddenly drop intensely, a larger drop than the Alternator Regulator could compensate for. Thus for a second, the alternator was cramping a lot of power into the system, thus the flashing light.

As I said before, the problem is 80% fixed. I just need to re-wire the fans to stay on whenever the A/C is selected (not just when the clutch is engaged) I just want to confirm that the wire i have to tap into is one of the pink/orange wires going into the white plug in the left of this picture: (taken underneath the passenger side dash, beyond the blower motor assembly)

http://i1246.photobucket.com/albums/gg618/vossler75/IMG_0113.jpg

It should be "hot" when the ignition is on, and A/C is selected, if i'm not mistaken. The other end if plugged into the A/C Diode in the wiring loom. If it works, that should lessen the load drop when the Clutch disengages, easing the burden on the regulator.

can anyone help me ID that that is the correct wire to tap into?

Thanks,

[Ron]

...
It should be "hot" when the ignition is on, and A/C is selected, if i'm not mistaken.
Correct.


The other end if plugged into the A/C Diode in the wiring loom.

???


If it works, that should lessen the load drop when the Clutch disengages, easing the burden on the regulator.

can anyone help me ID that that is the correct wire to tap into?

Thanks,
To make the Fans come on whenever the AC is ON w/o affecting the AC clutch, find the junction where the pin(K) wire splits just before going to the Compressor and move the one going to the Diode over to the other side of the Low Pressure Switch.

This is virtually the same thing I think you are saying to do (snip it at the diode... see "???" above)...you must separate the two Pink wires or the compressor will not cycle if you run a tap from the Pink-Orange to the back side of the diode...and if you run it to the front side of the diode, the otterstat will energize the clutch along with the fans.

I doubt this is going to help the Battery light situation...the light comes on ONLY when the alternator has LESS power than the battery, not more (than it knows what to do with...or such). A bad regulator or possibly ground could do it, but IIRC you have tried all of that...

Did you try a standalone switch to control the clutch for a test as suggested in the other thread?