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.