Got the car running and the alternator was working 14volts no gen light. didnt have it running long because of some leaking issues. However towards the end of its short run time. The generator light came on and it dropped down to 12 volts. I was running the car by gas pedal so the rpms weren't too low. There is a blue wire that connects to the back of the alternator that goes to the alarm. Does that need to be energized? Have the alternator out for testing and rebuild if needed. Just checking to see if I missed something first. Thanks in advance
Dave

It's junk, I will trade you a 2.0 liter motor for your junk 3.2

That's what I love about this site. People are always looking out for you. Thanks for the heads up Rich. Sounds like a deal to me. Since I'll be going back to 2.0 I don't think I'll need the rebuilt 915 with the Vellios kit. I heard they're heavy anyway. So if you have a serviceable 901 we can swap those too. Hahaha

Mine is a fresh rebuild so you may have to give me some cash to make it an even trade....

Whatever you think is fair. Wouldn't want to take advantage.

depends on which alternator you have, but wiring is approximately the same for all 3.2s with internal regulator

no clue about your blue wire to an alarm - that is not an oem feature

look at the wiring diagram in your Bentley 84-89 Carrera manual page 970-34 -35 - which if you don't have, get it - three different diagrams depending on year of your setup

the bosch alternators for 3.2s were good for about 35K miles

start here

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Larry
I'll have to get the manual. Heres a pic of the blue wire. It's on the left. This is the factory harness on the motor.
Click to view attachment p

Hey Dave
Isn't the blue wire to the alt. charge lamp ?
Not hookey up no chargee ?
Rory

Rory
I don't have the exact schematic for this years so I'm not sure. I'm taking the alternator for checking rebuilding tomorrow. It worked when I first checked so I think it just gave up the ghost.
Dave

Only alternator pics I have. Not a 3.2

According to the diagram I have on the Patrick motorsports jumper harness. The blue Wire is the generator light. Right on Rory.

Hey Dave
I'm no Thomas Edison but as I recall the charge lamp is necessary to 'excite'
the alternator. No lampee, no chargee.
Check that the lamp filament has not burned. (you saw 14v at startup ?)
Rory

Yes , 14 v to start with. The light was on after it stopped charging. So it is goo. Still came on with the key.

yes that blue wire is factory. however the post is small and easy to damage.
if your that far, just pull the alternator completely and have it checked?

Already there. Will have it checked tomorrow.

Hey Dave
I bet it turns out to be dirty contact rings on the armature or stuck / worn brushes.
Rory

Sucks eh Dave mine has been fully rebuilt and only makes 13 volts and is functioning according to the charge light ,under load it basically turns to ,guy that rebuilt it is happy to revisit and '' says take it out and I will check it '',then I told him whats involved he replied ''when ever you can".
PITA really its just a shit job to do but that's what we have with these conversions eh ?

It's definitely a PITA to have to drop the motor to change an alt. It's like the car gods are trying to make me earn it. I guess it's like labor pains, once it's sorted this crap fades to the background. Mines being checked now.

Just got the alternator back. Had a rebuild shop check it out. All good, brushes and all. We think my quad gauge may be the problem. I had New Vintage build a quad gauge in 2010. The blue wire is needed to excite the alternator. The warning light may be led and affecting the flow. So here's what happens.
power the car
one side of the light is hot ( lights off)
put a test light on the blue wire side and the gen light comes on but the test light does not light up. Maybe no enough flow.
If i cant get it sorted thru the light. I'll just skip the light and make the blue wire hot from the key.
I would like a warning light to get my attention but I dont have to have it.

Hey Dave
Can you live with a conventional bulb for the alternator ?
You'll only see it until the engine starts.
Only you'll know.
Rory

The gauge is a custom quad that I can't change over like a stocklight. Lack of resistance is the issue with the led light. So they run a resistor in parallel to solve that. That's my plan on solving the issue.