DMCH alternator

[Bitsyncmaster]

I installed a new DMCH alternater PN 110101.

When the engine is at idle with blower on #4, headlights on low beam and AC running the voltage is 14.2 volts but every 18 seconds there is a quick dip to 13.0 volts. It's like the alternator switches off every 18 seconds. I did not notice it with the accessorys turned off but the battery could be holding the voltage without the loads.

Is this normal for this alternator?

[DMC-81]

Hi Dave,

I have the same alternator that I just ran for the first time yesterday and today, as I just got my engine running again. As I was watching the instruments like a hawk, I noticed a similar dip in the voltage gauge. I had my heat on full speed (to help bleed the cooling system), the radio, and the high beam headlights. It was a momentary dip and I didn't notice the accessory performance suffer. I did not time the dip or the interval, but I will next time I run the car.

Also, I read that with this alternator, the battery light blinks on startup as it is doing some checks, and then goes out after the car starts. Is that your experience as well?

Dana

[refugeefromcalif]

Did DMCH stop selling the Motorola 140 A alternator? The part # that was posted specifies a 120 A alternator.
I ask because I had a Major charging issue start today.

George

[Bitsyncmaster]

Hi Dave,

I have the same alternator that I just ran for the first time yesterday and today, as I just got my engine running again. As I was watching the instruments like a hawk, I noticed a similar dip in the voltage gauge. I had my heat on full speed (to help bleed the cooling system), the radio, and the high beam headlights. It was a momentary dip and I didn't notice the accessory performance suffer. I did not time the dip or the interval, but I will next time I run the car.

Also, I read that with this alternator, the battery light blinks on startup as it is doing some checks, and then goes out after the car starts. Is that your experience as well?

Dana

Yes my battery light blinks with the key turned on and engine not running. I'm going to do some troubleshooting as I think of things to check. First thing I want to check is to feed the battery light wire with a bench supply and the light bulb just to verify that circuit is not glitching.

[DMCMW Dave]

Yes my battery light blinks with the key turned on and engine not running. I'm going to do some troubleshooting as I think of things to check. First thing I want to check is to feed the battery light wire with a bench supply and the light bulb just to verify that circuit is not glitching.

Normal operation for that unit.

[kings1527]

I installed a new DMCH alternater PN 110101.

When the engine is at idle with blower on #4, headlights on low beam and AC running the voltage is 14.2 volts but every 18 seconds there is a quick dip to 13.0 volts. It's like the alternator switches off every 18 seconds. I did not notice it with the accessorys turned off but the battery could be holding the voltage without the loads.

Is this normal for this alternator?

I have the same unit and it operates exactly the same way.

[mluder]

Me three...

The battery light blink is normal operation for this unit.
I also have dips in voltage when the AC is running full on. Hasn't been a problem for daily use. I think it's a function of us comparing this car to our more modern daily drivers. IN all honesty I'm not sure that the instruments on modern cars are not just idiot appeasers... In other words, they don't display accurate data but rather go to "normal" operating readings at start-up just to make us think everything is OK.

Cheers
Steven

[DMCMW Dave]

The most important thing you can do when installing this, or any, alternator is to clean the grounds. This includes taking the alternator mount off the engine and cleaning the sides that contact the alternator and the back that contacts the engine. New hardware is a good idea too.

[Bitsyncmaster]

Grounds would not cause this 18 second cycle.

Using a bench power supply for the “battery light” circuit makes no change to that 18 second voltage dip.

Measuring current through a shunt on the alternator output the current is 64 amps at idle speed 950 RPM, blower on #4, Lights on low beam and AC on normal. Every 18 seconds that current dips quickly (less than 50 ms.) to 48 amps. It then rises linearly back to 64 amps in 1.2 seconds.

Measuring voltage with the same loads I get 14.7 volts with a dip every 18 seconds to 13.4 volts. The dip is more of a sine wave also for 1.2 seconds since the battery is supplying some power when the alternator switches to lower current.

I wonder why that alternator voltage regulator is doing that every 18 seconds.

[David T]

Grounds would not cause this 18 second cycle.

Using a bench power supply for the “battery light” circuit makes no change to that 18 second voltage dip.

Measuring current through a shunt on the alternator output the current is 64 amps at idle speed 950 RPM, blower on #4, Lights on low beam and AC on normal. Every 18 seconds that current dips quickly (less than 50 ms.) to 48 amps. It then rises linearly back to 64 amps in 1.2 seconds.

Measuring voltage with the same loads I get 14.7 volts with a dip every 18 seconds to 13.4 volts. The dip is more of a sine wave also for 1.2 seconds since the battery is supplying some power when the alternator switches to lower current.

I wonder why that alternator voltage regulator is doing that every 18 seconds.

It is very hard for the alternator to put out a lot of amps when the motor is not going fast. No alternator can put out it's full rated output at idle. My guess is to prevent overloading (and overheating) the alternator, the voltage regulator cycles it like the duty cycle of the A/C so it can handle the power without overheating. A better test would be at or above 1200 RPM. The alternator is a little "undocumented" especially when it comes to the blinking.

[Ron]

$.02:

Don't hold me to it, but without looking at that type before, I'd bet it's odd behavior(s) is due to not utilizing a battery sensing circuit, as expected?? :
http://dmctalk.org/attachment.php?attachmentid=35396&stc=1

[Bitsyncmaster]

$.02:

Don't hold me to it, but without looking at that type before, I'd bet it's odd behavior(s) is due to not utilizing a battery sensing circuit, as expected?? :

Good idea Ron. I was looking at patents today to see if anything new was showing on Automotive regulators. Looks like some new ones are using a microprocessor which would explain the flashing self test.

[Bitsyncmaster]

So it looks like I should try connecting the "S" pin to the battery (always 12 volts).

Why would the "S" pin need a heavy wire if all it does is remote sense the voltage?

Connector is labeled S F L P.

We use the "L" for the light. Some use the "F" with a switched 12 volt feed. So what is the "P" for?

[Bitsyncmaster]

Found the definitions.

[Ron]

So what is the "P" for?(P)ulse.
For diesel engines...no ignition/tach signal!

NOTE: Your pic says, "battery positive", but normally it should be fused and switched B+.
You could simply strap it to the alternator's battery terminal, but they want it wired to ignition due to ~1V drop across the wiring....
[Assuming standard setup here]

[DMCMW Dave]

NOTE: Your pic says, "battery positive", but normally it should be fused and switched B+.
You could simply strap it to the alternator's battery terminal, but they want it wired to ignition due to ~1V drop across the wiring....
[Assuming standard setup here]

Actually if you just leave it disconnected it will internally regulate. Which is the "normal" installation. Just the output wiring bundle, and the one wire to the idiot light.

[refugeefromcalif]

Did DMCH stop selling the Motorola 140 A alternator? The part # that was posted specifies a 120 A alternator.

George

Anybody know? I've searched the DMC website and only find the 120A.
I've had the the Motorola 140 installed for about 2 years and yesterday had an issue with it, (Or the charging system in general). Thunderstorms halted my diagnostics.

George

[Ron]

Actually if you just leave it disconnected it will internally regulate. Which is the "normal" installation. Just the output wiring bundle, and the one wire to the idiot light.Thanks!
For future reference, do ya know if it is a SFLP or SILP??

[DMCMW Dave]

Thanks!
For future reference, do ya know if it is a SFLP or SILP??

No, I don't.

[Bitsyncmaster]

Thanks!
For future reference, do ya know if it is a SFLP or SILP??

Both connectors (Johns and DMCH) are exactly like the picture I posted. SFLP

I don't think the remote sense will fix the "dip" problem but I'm going to test it anyway. I would assume if the sense line has a lower voltage than the output terminal on the alternator it will boost the voltage. I'm not worried about voltage drop over the wires since I have a 4 AWG wire about 2 foot long going to my buss bar. I'm seeing 14.6 volts on the buss bar to engine ground.

I will also try powering the "F" terminal to see if that corrects the "dip".

Since I saw the dip go to 48 amps, maybe other cars that only run the stock idle ECU (775 RPM) can only provide 48 amps and they would not see the dip.

Does anybody know what the flashing would be for normal self test and what it would be if it found something wrong?

[dustybarn]

Actually if you just leave it disconnected it will internally regulate. Which is the "normal" installation. Just the output wiring bundle, and the one wire to the idiot light.

Yes, there does appear to be an internal resistor that makes connecting the "S" terminal optional. I elected to connect mine to the main passthrough stud below the bulkhead connections under the coil cover. A thin wire is sufficient because it's just a voltage-sensing wire.

[Bitsyncmaster]

$.02:

Don't hold me to it, but without looking at that type before, I'd bet it's odd behavior(s) is due to not utilizing a battery sensing circuit, as expected??

Looks like Ron the man.....:rock_on:

I first checked the voltage on the "S" terminal and it was zero volts. I was expecting it to be pulled up to the battery voltage. I then connected it to the battery through a 1 Kohm resistor so I could measure the current that "S" terminal would draw if always powered. Result is 187 ua.

Connected the "S" wire directly to the output terminal of the alternator. Started the car and put the loads on and waited and waited and waited for the dip (I'm just looking at the dash volt gauge). No dip seen so I disconnected the "S" lead (I'm just using an alligator clip lead for now), and did see the dip occur. Connected it back up again and no dip seen.

So it looks like I will permanently wire that "S" lead to the alternator output post.

I measured the voltage at my buss with it connected and it was 14.49 volts, without it connected it was 14.44 volts all when my loads were running.

I did discover a bug in my battery disconnect relay during this testing where when I switch the AC to off with the blower and headlights still on it glitches the disconnect relay and turns the engine off. I will need to fix that glitch.

[Bitsyncmaster]

Without connecting the "S" wire to battery voltage this alternator will flash the dash battery light. That flashing starts intense and then it looks like the duty cycle decreases so the flash gets less intense, then it repeats. This is all when you just turn the key to on (engine not running).

Connect that "S" wire to battery voltage and that flashing is no more. Light just comes on and stays on when engine is not running.

I guess we should have questioned why it was flashing long ago.

[Ron]

...
Connected the "S" wire directly to the output terminal of the alternator. Started the car and put the loads on and waited and waited and waited for the dip (I'm just looking at the dash volt gauge). No dip seen so I disconnected the "S" lead (I'm just using an alligator clip lead for now), and did see the dip occur. Connected it back up again and no dip seen.

So it looks like I will permanently wire that "S" lead to the alternator output post.

I measured the voltage at my buss with it connected and it was 14.49 volts, without it connected it was 14.44 volts all when my loads were running.
I'm not familiar with your buss, but it sounds like you are all set. :thumbup:...A few notes for others:

First, I think it should be noted that the DMC "plug and play" wiring is probably ~OK as is.
But, for those with stock wiring, jumping the S terminal to the alternator's output terminal will give ~14.2V measured at the alternator terminal and ~13.2V measured at the battery -- Nothing to brag about....In fact, it can be worse than a true one wire setup (ie only has an output wire).

A much better setup is to connect the S terminal to the battery (+) [or main accessory feed/buss junction], which will give ~15.4 at the alternator terminal [...] and ~14.2V at the battery -- Ideal!
The longer the feed wire, the more this is needed.

Hope this helps....

P.S. What I would like to know about is the flashing.....

[Tillsy]

Great work Dave, my IT instincts had been telling me these reports of a flashing light with the new alternator meant "error".

[Bitsyncmaster]

Looks like this new alternator uses a microprocessor in the voltage regulator. Wish we could get more info on the error codes.

[DMC-81]

Very interesting!! Let me see if I follow....out of the box, the alternator self regulates after blinking on start up, but with the S terminal optionally connected to battery positive, you avoid the blinking light and the minor voltage dips?

A few questions if I may:

- are we saying the S connection provides more voltage performance?

- does this connected S terminal hurt anything on this unit, or on the other hand, help the unit last longer? i.e Are the voltage dips an intentional rest period?

- should the S connection be fused?

- if we want to connect the S, do you need a new plug, or can you add a wire to the 1 wire plug?

- and finally, would the solid brown ducy wire serve as a connection for the S terminal?

Thanks,

Dana

[dustybarn]

Very interesting!! Let me see if I follow....out of the box, the alternator self regulates after blinking on start up, but with the S terminal optionally connected to battery positive, you avoid the blinking light and the minor voltage dips?

A few questions if I may:

- are we saying the S connection provides more voltage performance?

- does this connected S terminal hurt anything on this unit, or on the other hand, help the unit last longer? i.e Are the voltage dips an intentional rest period?

- should the S connection be fused?

- if we want to connect the S, do you need a new plug, or can you add a wire to the 1 wire plug?

- and finally, would the solid brown ducy wire serve as a connection for the S terminal?

Thanks,

Dana

Connecting the S terminal to the vehicle power bus may provide a steadier voltage because any voltage drop in the alternator wiring is automatically compensated for (this has been my experience). There should be no effect on the longevity of the unit; it's designed to work that way. I see no compelling reason to put a fuse in the S lead because it carries almost no current.

[Bitsyncmaster]

Connecting the S terminal to the vehicle power bus may provide a steadier voltage because any voltage drop in the alternator wiring is automatically compensated for (this has been my experience). There should be no effect on the longevity of the unit; it's designed to work that way. I see no compelling reason to put a fuse in the S lead because it carries almost no current.

+1

Using the S terminal is a pretty common wiring option in a lot of cars. You would need to get a new connector with that pin connected to a wire or find the correct pin to install into the existing connector. I pulled the pin from my old connector which happened to have that larger pin (the other three are smaller). I don't think anyone ever uses a fuse for that wiring. It just draws micro amps of current. But if the wire insulation were to get cut and contact ground it would melt the wire (work like a fuse link). I used 16 AWG wire on mine.

Remote sensing is always used in large high amp power supplies for electronic units. The power supplies even have both ground sensing and + sensing. When producing 5 volt, 3.3 volt and now even lower voltage used for electronic circuit boards a voltage drop of even 0.1 volt over the wiring can cause problems.

[DMC-81]

Very cool. Thanks for all the information. Very helpful!

So, would the solid brown ducy wire serve as a connection for the S terminal, or not so much? It's just that it is really handy to the alternator, and not being used.

Also, this alternate 2 wire plug seems like a good new product for those running this unit.. Hint hint.... :smile:

Although I wonder if it will void the warranty?

Thanks,

Dana

[Bitsyncmaster]

Very cool. Thanks for all the information. Very helpful!

So, would the solid brown ducy wire serve as a connection for the S terminal, or not so much? It's just that it is really handy to the alternator, and not being used.

Also, this alternate 2 wire plug seems like a good new product for those running this unit.. Hint hint.... :smile:

Although I wonder if it will void the warranty?

Thanks,

Dana

I don't have the documentation of the original two control wires used on the Ducy. You really would not want to connect the sense wire to a circuit to far from the battery or your voltage may go to high (above 15 volts) elsewhere in the car. I just put a ring terminal on the S wire end and bolted it along with the heavy output wire onto the output terminal of the alternator.

[Ron]

I posted GM docs with a lot of the answers and more in the Resources Section- Alternators - Delco Style Wiring and More (http://Alternators - Delco Style Wiring and More)

Bottom line is you can basically put their sensor wires in any of the discussed places (or not use it, for some), as long as the Battery v/s Alternator voltage does not differ more than 0.5V at maximum output (6000 alternator shaft RPM, NOT engine RPM).

[DMC5180]

I don't have the documentation of the original two control wires used on the Ducy. You really would not want to connect the sense wire to a circuit to far from the battery or your voltage may go to high (above 15 volts) elsewhere in the car. I just put a ring terminal on the S wire end and bolted it along with the heavy output wire onto the output terminal of the alternator.

The original 81 wire diagram still shows the brown wire to the alternator. If the schematic can be trusted, the origin is the large white wire cluster splice junction in the main harness near the fuse box.

[Chris 16409]

Why hasn't this "S-wire" conversation ever been brought up before? Is this only necessary for Houston's new unit, or would we all benefit from this? Hervey doesn't say to do this for his alternators.

[DMC5180]

It's not necessary for either, but appears to smooth out a curtain condition with the pulsing battery light, which is just an odd feature of that internal regulator that we are not accustomed too seeing.

Most likely will work with a Hervey unit too if it's the same 4 pin connection.

[Ron]

Why hasn't this "S-wire" conversation ever been brought up before? Is this only necessary for Houston's new unit, or would we all benefit from this? Hervey doesn't say to do this for his alternators.
+1 Dennis...and because hooking the wire to the B+ is the same thing as not hooking it up at all, for most alternators -- they will get it internally.
All the points will "work" for most units.

If you want simplicity (or people not returning units they don't understand ;-), use it as advertised/accompanying docs.
If you want a "good", "safe" setup, hook it to the common distribution point (Starter solenoid, main terminal or Buss).
If you want "the best" setup, try it at/near the battery, making sure the battery v/s alternator voltage does not exceed the amount stated in the regulator's docs (0.5V for all GM SI style alternators). If out of spec, it should work well at the junction point. But, like Bitsy said, don't get too far from the battery.

I would definitely check the bat v/s alt voltage difference if I used the existing brown wire on a D since the power comes from the Alt main, to the junction point, through the ignition solenoid, and back to the alternator (through the crappy bulkhead connector ;-) -- That's a long way. Seems the starter would be a better solution, since it's inches away, IMHO.

FWIW- Actually the idea works for old mechanical regulators. (GM ran most of theirs to the starter solenoid, battery or horn relay; Ford to the solenoid on the firewall next to the battery, since the junction was there as the starter didn't have a solenoid mounted to it...); Chrysler's only had a field wire...).

[[email protected]]

For all us simpletons out here could one of you experts perhaps draw a diagram or shoot some photos of each of these setup connections. I just ordered a new alternator from DMCH and I'm now very confused, I'm replacing one of the Auto Zone alternators. Thanks in advance.

[Drive Stainless]

For all us simpletons out here could one of you experts perhaps draw a diagram or shoot some photos of each of these setup connections. I just ordered a new alternator from DMCH and I'm now very confused, I'm replacing one of the Auto Zone alternators. Thanks in advance.

Did the lifetime warranty run out?

[Ron]

I just ordered a new alternator from DMCH and I'm now very confused, I'm replacing one of the Auto Zone alternators. Thanks in advance.See second diagram HERE (http://dmctalk.org/showthread.php?40-All-Wiring-Schematics)
If that doesn't clear it up for you, tell us which DMCH alternator you are getting (or maybe call the them).

[Ron]

Something is wrong with the link in post #32. This should work:
http://dmctalk.org/showthread.php?12224-Alternators-Delco-Style-Wiring-and-More

[DMC-81]

Looks like Ron the man.....:rock_on:

I first checked the voltage on the "S" terminal and it was zero volts. I was expecting it to be pulled up to the battery voltage. I then connected it to the battery through a 1 Kohm resistor so I could measure the current that "S" terminal would draw if always powered. Result is 187 ua.

Connected the "S" wire directly to the output terminal of the alternator. Started the car and put the loads on and waited and waited and waited for the dip (I'm just looking at the dash volt gauge). No dip seen so I disconnected the "S" lead (I'm just using an alligator clip lead for now), and did see the dip occur. Connected it back up again and no dip seen.

So it looks like I will permanently wire that "S" lead to the alternator output post.

I measured the voltage at my buss with it connected and it was 14.49 volts, without it connected it was 14.44 volts all when my loads were running.

I did discover a bug in my battery disconnect relay during this testing where when I switch the AC to off with the blower and headlights still on it glitches the disconnect relay and turns the engine off. I will need to fix that glitch.

Hi there,

I'm just getting around to connecting the S post as described. Question: does anyone have a part number for the female pin (or a compatible connector to remove one from) that you need to add to the DMCH connector to complete this task?

Thanks a bunch!

[Bitsyncmaster]

Hi there,

I'm just getting around to connecting the S post as described. Question: does anyone have a part number for the female pin (or a compatible connector to remove one from) that you need to add to the DMCH connector to complete this task?

Thanks a bunch!

There are quite a few people selling the connector with all the wires and pins installed. I pulled the pin I needed from and extra alternator connector I had and installed it into the new connector.

[DMC-81]

There are quite a few people selling the connector with all the wires and pins installed. I pulled the pin I needed from and extra alternator connector I had and installed it into the new connector.

Thanks Dave. I found one... AC Delco, part # 3102-05413205

Cheers,

[Chris 16409]

Dana, here is an alternative part number:

https://www.napaonline.com/en/p/NW_787128?searchCategory=11.9&searchIndex=App

Napa 787128

[DMC-81]

Dana, here is an alternative part number:

https://www.napaonline.com/en/p/NW_787128?searchCategory=11.9&searchIndex=App

Napa 787128

Excellent, thanks Chris!

[DMC-81]

Well, couldn't find the Napa part locally, but it crossed to this Dorman 85854 which is exactly the same connector as the one on the alternator, except it has 3 wires, instead of 1. It also looks the same as the Napa part.

49176 49177

I'll try to gently remove the "S" pin with the red wire, or I'll just use this connector.

Question: What's the trick to remove the pin, and can you remove both pin and wire?

Thanks!

[DMC5180]

You could just use the red wire. Put a ring terminal on it and connect it to the batt + post with the main Alt wire. Doing this will stop the BATT light flash/pulsing with the key ON without the engine running.

The black wire can be removed.

The correct way to remove the terminal is with a terminal pick tool like this http://www.repairconnector.com/weather-pack-extractor-and-pick-tool-set-3-pieces/

The green pick is for small weatherpack terminals like the Black wire in that connector.

These pick tools come in handy for releasing lots of electrical terminals and relay socket terminals. I have 3-4 of them.


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[DMC-81]

Thanks again Dennis. Great info on those tools. I'll have to look for them.

I decided to just use the new connector, instead of risking damage by removing a pin. I tested the brown Duceiller wire for the S connection, and it was successful in turning off the flashing condition with the key on.

49210

This is a cleaner setup in my mind, but I realize I'll have to test the voltage difference as described earlier by Ron in post 32 and 36 before I wrap it up permanently.... (It'll be a while until I can start the car again). If it fails this test, I'll connect the red wire to the alternator post.

As far as the testing goes, I'm looking for a greater than 0.5 volt difference between the alternator and the battery at maximum alternator output.

Question: I assume I test with the engine running at a fairly fast idle, and for:
1) the alternator I test at the output post on the back (with the 2 groups of 6 brown wires attached), and:
2) the "battery", I test the voltage at the brown Duceiller wire where I connected it

Is that correct, and are there additional tips? What about lesser alternator output speeds?

What's the downside if the voltage difference is out of spec? Edit: I found the answer to this question in Dave M's post # 31.

Thanks,

[Rich_NYS]

lookin' good Dennis, what's that stuff sleeved on your wires? I'm guessing heat shield...I want to put some on my wires.

[DMC5180]

Rich, it's Dana not me. The covering is thermal heat protection sleeve.


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[Rich_NYS]

Rich, it's Dana not me. The covering is thermal heat protection sleeve.


Sent from my iPhone using Tapatalk

Sorry 'bout that, thanks for the info... !

[DMC-81]

Thanks again Dennis. Great info on those tools. I'll have to look for them.

I decided to just use the new connector, instead of risking damage by removing a pin. I tested the brown Duceiller wire for the S connection, and it was successful in turning off the flashing condition with the key on.

49210

This is a cleaner setup in my mind, but I realize I'll have to test the voltage difference as described earlier by Ron in post 32 and 36 before I wrap it up permanently.... (It'll be a while until I can start the car again). If it fails this test, I'll connect the red wire to the alternator post.

As far as the testing goes, I'm looking for a greater than 0.5 volt difference between the alternator and the battery at maximum alternator output.

Question: I assume I test with the engine running at a fairly fast idle, and for:
1) the alternator I test at the output post on the back (with the 2 groups of 6 brown wires attached), and:
2) the "battery", I test the voltage at the brown Duceiller wire where I connected it

Is that correct, and are there additional tips? What about lesser alternator output speeds?

What's the downside if the voltage difference is out of spec? Edit: I found the answer to this question in Dave M's post # 31.

Thanks,

I was finally able to test the voltage with my new plug and the "S" wire connected to the original brown Duceiller wire. I got 14.59 volts at the alternator output terminal and 14.53 volts across the battery.

What are your thoughts? Is that a good result?

[Drive Stainless]

I was finally able to test the voltage with my new plug and the "S" wire connected to the original brown Duceiller wire. I got 14.59 volts at the alternator output terminal and 14.53 volts across the battery.

What are your thoughts? Is that a good result?

Sounds great!

[DMC-81]

Sounds great!

Thanks Matt. I measured it at a steady idle (after warm up). I didn't have an assistant to do it at a fast idle but I assume the voltage difference wouldn't creep up dramatically as the RPMs increase due to the built in voltage regulator. Is that a correct assumption or should I test again?

[Bitsyncmaster]

Thanks Matt. I measured it at a steady idle (after warm up). I didn't have an assistant to do it at a fast idle but I assume the voltage difference wouldn't creep up dramatically as the RPMs increase due to the built in voltage regulator. Is that a correct assumption or should I test again?

Your voltage is probably regulating fine. It should not climb much more than 14.6 volts. It's only when you have a lot of load and low RPM that it may fall below that value.