Issue with alternator, engine, trans
 

Hello

I'm still struggling to find the fault in my alternator.
I tried two of them.
The first one was working engine cold and once it was hot, I had to give it a big revv so that it would go back to 13.7v. The battery indicator would light up or flicker.

Second one with regulator connected it worked engine cold once hot it goes down little by little until no charge at all. Unplugged regulator it charges when cold and once hot it charges when I drive but then to a stop it no longer charge. No battery indicator with this one.

I am trying to fix something similar in my '05 3.0 (6cyl). I don't know how old my My OEM Valeo alternator is, but it puts out 13.1 - 13.6 volts when driving, but only 11.7 -12.2 volts when stopped at a light.

I already changed the voltage regulator in the back of the alternator. I am now replacing the whole alternator with a new Valeo one (not rebuilt).

I read your previous posts, you have already replaced your alternator twice ? Did you buy new alternators or rebuilt?

Can you take an alternator to an alternator/starter shop in France and have it tested outside the car?

The last one I actually have is from a alternator specialist shop he gave me an old Bosch one with all parts refurbished as new and new regulator. There is no reason both alternator would be faulty.

Someone told me it could be the engine ground connexion but the mechanic who changed the last alternator told me it was fine but I'm not sure he really checked.

If you have 2 different problems with 2 different alternators chances are there is something wrong with both, not at all unheard of.

I agree...the chances both alternator are bad are low.

If my charging is not fixed, I am also going to look at my ground strap AND the cable that comes from that battery that attaches to the jump connection in the engine bay.

Grounds are just as important as the positive connections. The best way to check is by looking for a voltage drop (that should have done by the mechanic who checked). There is a good post a few threads down that shows how to do that.

Do you have a clamp voltmeter? I'm curious on the amp output reading.

Update: My new (not rebuilt) Valeo 140 amp Alternator seems to have solved my problem. I am getting a steady 13.7-13.8 volts at idle and while driving as measured by my cigarette lighter volt meter.

I am a little surprised replacing the voltage regulator on my old alternator did not fix this issue. The voltage regulator was pretty well worn with uneven bushes.

Let's see if we can help OP with his issue.

I'm willing to try that theory but in France I'm not sure there is any new ones. I can find Bosch refurbished as new from official stores but it's 700euros.

Just buy from an ebay seller and pay the international shipping:



https://www.ebay.com/itm/275505819642