I am hoping that someone with a lot more experience with an FB can help me out here. I bought my girlfriend an 83 for her 30th B-Day, her first car was an 84 FB. A few day’s after I got it I changed out the stereo to a newer Alpine. I used the original wiring by making connectors. A couple of days after that I noticed that the lights were dim. I though it might be the install so I took it out and checked all of the connections. They’re all tight. Since then I’ve changed the alternator, battery, checked and cleaned the factory grounds and added grounds from the (-) Bat Terminal and the Alternator case to the X-13 ground point. I’ve also taken the Alt. back to the store to have it re-tested after I changed the Bat. I have run a multi-meter across just about every inch of this car trying to find a short, but can not. Then I did the “old school” Alt test. Take the neg. cable off the Bat. When the car is running and the car should STAY running and it doesn’t (and no I did not put the cable back on until I turned the key off. I rather like the diodes in the regulator). I also noticed that both sides of the fuses in the block have a direct short to ground; is this normal for this car. I did mechanics for a long time, although I have to admit I have been out of it for a”few” years know and a little rusty. Is there something in an FB that goes out and causes this condition? I did check all of the posts I could find related before I started this one. HELP ME PLEASE, the old lady is killing me to get this thing back on the road!!!

 

i would say a bad ground, but you have already covered that. all that i could say is that you may need to clean the connections from the harness to the alternator or the grounds that are on the fuse block aren't supposed to be there.

i am one of the rotary guys here, but i am horrible with wiring. the other guy should chime in tomorrow morning.