Ok I've got a 91 rs with an alternator problem. I can't figure out what the problem is. All the wires to the alternator or a getting juice but the alternator won't charge. I replaced the first one but the new one didn't make any difference, then I went and had them tested and it showed they were both good alternators. There's no connection problem with wires, everthing is on there fine. And I'm pretty sure there's no ground problem. Any help appreciated.

 

is the exciter wire working

the smaller wire on the two prong terminal should be hot with the ignition on

 

it shows to be....I've replaced the alternator and battary and it still won't charge.

 

do you know for a fact that theres nothing wrong with the battery? i'd check that, but also all of those damn fusible links or whatever. i'm talking about that sealed fuses that blow, you can't change without changing the whole wire and are a pain in the A** to diagnos. I had this problem with my '86 z28 (i know, carbed vs injection, but i'm pretty sure the carb charging siystem is the same as my old tbi on my bird) and it turned out to be the wire running from the alternator to the starter and with that damn fusible link blown, it interupted the charging circuit. just a thought, give it a try. simple, yet a b**** to find.

 

try chaging out the harness at the altanator side fixed mine when it acted just like that. like 3 bucks at auto zone the harness wasnt makin contact but you cant really check to see if it is.