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Alternator - voltage regulator - ammeter challenges

pederfedde

New member
3
0
1
Colorado
I have a 1965 Bonneville 4 door hardtop with 389 4barrel -all original with electrical charging challenges.

We have owned the car since 1967 and it has been sitting since 1984. Brought it out and getting it running again. The lights were flickering and the ammeter pulsing so I had the alternator rebuilt. Now the flickering is gone, but the ammeter goes to discharge at idle with lights & air conditioning on and in drive with brakes on, at this point the blinker blinks once ever 12 seconds or so.

Back in the 1960’s my dad experienced the car burning out alternators on a regular basis. Got rid of the die hard battery and seamed to fix the alternator burnout problem. But he remembers it being very frustrating. My dad did his own mechanic work for the most part.

I recently had the alternator rebuilt and the guy used a 90amp stator and a larger rotor - this maxed out the ammeter both on the charge and discharge side. I have a new voltage regulator on it as the alternator guy burned out the one on the car when testing it. 😔

The alternator rebuild guy swapped out the 90 amp stator for a 60 amp one and put in a 42 amp rotor. Running down the road the ammeter dial is steady to the right of center about 3/4 of the way to the first mark right of center. It was originally supped to be a 55 amp alternator (10DN).

Prior to any recent alternator rebuild and with the flickering lights the ammeter was just to the right of dead center at road speed and rarely went into discharge.

Any guidance on this issue. It seems to be working other than major discharge when stopped, or low rpm. It has the three prong voltage regulator.

Could it be that this car was originally equipped with the transistor voltage regulator and it was changed to a mechanical one and shouldn’t have been, probably not, but not sure.

Does the horn relay have anything to do with it, or do I need a better voltage regulator or a new alternator?

The car is all stock options and no added electrical stuff since new.

Thank you.
 

pederfedde

New member
3
0
1
Colorado
I have a volt meter and have used it. Is there a specific place I need to check? There is no drop between the battery and the alternator. It rests at about 14.5 v at idle with the car in park with AC and all electronics on but put the car in drive and at idle it drops to around 12 v which drops the ammeter to discharge.

Is there a difference for this car using a 55 amp stator vs a 60 amp stator? The book says to not use the 60amp alternator with a car that is supposed to use a 55 amp alternator.
 

melsg5

Staff member
SUSTAINING MEMBER
19,442
67
48
Your alternator is not charging the battery if it drops to 12V.
What is the rebuilder's thoughts on what he did to cause this condition?
Perhaps you should look into a different rebuilder .
Why is he mixing all these different parts instead of sticking with what the alternator originally had in it?
______________________________
 

melsg5

Staff member
SUSTAINING MEMBER
19,442
67
48
I was under the impression that you were attempting to retain the originality of the 1965 alternator. You can buy a rebuilt 1965 alternator at any NAPA or other parts store. Why are you dealing with a rebuilder on a alternator that isn't the original one?
 
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