Hello gentlemen, new owner here. 92XJS V12. In advance, any help is greatly appreciated. I recently purchased this Jag and one of the first things I had to do was replace the alternator. Not a hard job, pretty straight-forward. Afterward, the new unit charged like a champ, 13.7 volts idling. I didn't start the car for a couple of days after that and now the alternator is not charging at all. Am I missing something? I kept the battery dissconected the whole time I was installing the new one so no unwanted or accidental sparks, the battery wasn't dead both times it was cranked. My parts guy says I must have got one with a bad or weak regulator and he is getting me another one. Anybody ever run into this problem before. Again thanks for any help.

 

I'm betting on a faulty alternator but some XJSs had an alternator output"dump module" which might be a problem.

I can't really remember the specifics but we can do some digging if the need arises.

Cheers
DD

 

I had similar problem. It was a bad voltage regulator in the Alternator that I put on. The connections are less than tight for the connection from the laternator to the voltage regulator also.
David

 

Thanks guys. I'll post the resultswhen I get it figured out.