Originally Posted by 4.7stroker
Well lets start with the basics, there are 2 wires that connect to the back of the alt. One has a 2 pin plug the other bolts on. Are they hooked up? Also one of the wires has a 2 pin connector about 8" from the alt end is it hooked up? You will need 12vdc exciter voltage to "start" the alt are you getting that?
Why do you say your alt is not working? is it just a gauge issue or is your battery going flat?
Guage does move but stays in red, Battery isnt taking a charge and not reading amperage output from the alternator when installed in YJ. I took the alt and batterey out and had tested. All bench test fine with proper output, even tried a second known good alternator and same issue.. so thinking is the wiring.
All 3 wires on the back of the alternator are hooked up, and making a good connection. I have a single red wiire that bolts to a post connection and a white 2 prong plug with a red and brown wire in it. I dont have a 2 prong plug a few inches down the line like you mentioned, unless I am understanding wrong. This is the factory wire and wasnt altered. Basically the red wire in the plug and red wire bolted on tie back in and connect to a relay? on the firewall. The brown wire in the plug runs back in the loom and back into the firewall(Im assuming to the ignition switch or something.. havnt traced it that far) Is this brown wire the exciter wire you mentioned? Do I test while running?