Alternator only charging at high rpm

[Dstat]

Bit of a strange one. I recently had a new waterpump fitted due to the old one leaking.

A few days later the car cut out. The plastic fuel connector near the oil cap had came off. Leaking fuel everywhere including on the alternator. I didn't think this would cause too much of an issue as fuel isn't conductive??

I reconnected the pipe and the car started back up with no further problems. A few more days have passed and now the battery and stop lights are coming on.

The car had a new alternator and battery in June so i would hope neither of these are at issue but you never know!

i have done a few basic tests. Ive done volt drop tests which were fine and also theres no problem with the cable going from the alternator to the battery. Ive changed the ringlet connector as a precaution.

Ive also checked the belt on the alternator and its nice and tight.

I only get 14v at over 2500-3000rpm. When the car is idling the volts drop back down to 12v. Ive also checked the exciter cable and get 11.5v here with the engine running.

I think its the alternator personally (even if it isnt more than 6 months old!)

just wanted to see if anyone else had experienced this problem and could offer some advice.

Thanks! Daryl

 

[ckings6056]

Alternator...... Check engine to chassis earth but most likely alternator I'd of thought

 

[Dstat]

I have no resistance from the alternator casing to the battery neg so presume its earthed ok. New alternator I guess!

 

[ckings6056]

Sounds that way I'm afraid.

 

[Paprika123]

New alternator. Same symptoms on my trophy. Got worse till the alternator light would only go out at the redline lol

 

[Dstat]

The latest update is that the car has been fine for the last 4 days. No battery light at all. I still suspect the alternator so if it comes back on I will be swapping it out. These french cars certainly keep you on your toes with their intermittent faults!