Hey guys I have a 1990 jeep Cherokee limited 4.0 4x4 and I bought it used and put in a new motor ( had one from my other jeep). Well I notice that the alternator gauge dosent read. So I figured bad alternator and since I was buying electric fans and some LEDs I figured just to buy a new 100 amp alternator because o don't know the condition of the old one. Well long story short I installed the new alternator and my gauge didn't move from the red. I have already refreshed all the grounds according to cruisers54 tips. I have yet to install thicker wire from the alternator to the relay( is that correct the wire from alternator to the actual relay and not battery post +??) and when I turn on my fans lights dim a lot ( it should be a total of about 25 amp draw from the fans together)

 

Im thinking it could be the voltage regulator. http://www.econofix.com/alt.html good information on here. (update) im not sure if we have an internal regulator or external. should have checked when i did my alternator last week.

 

Is the little 2 wire plug plugged into the alternator?

 

Yes lol

 

Well, one of those wires goes to the gauge and the other triggers the alternator to charge...........

 

Well when i check with the multimeter I get 14.3 and my guage says 0 but screw it its not a daily so I'll just deal with it I thought it would be simple to fix thanks guys

 

Somewhere between the alternator and gauge is an issue.