i just bought a 1986 trans am, 305 (i believe) tpi. when i got it it wouldnt hold a charge, replaced the alternator and battery, still not charging. the digital dash doesnt work at all, so i cant see the battery guage. was wondering what to check for. already looked at the battery, all wires connected fine. when new battery is in, it runs fine, then as it loses charge it will idle very high, then itll make a popping sound out of the intake when reved, then battery will go dead. will not restart unless jumped. when the car is connected to another car with jumper cables, it runs fine. im suspecting a wiring problem, but i haven o idea where to start looking. i need to get this thing running, its driving me crazy. also i noticed the taillights work, but when the headlights are on, the left turn signal will not blink at all. when the lights are off it works. any ideas? 1 more thing, when i stop hard or turn a corner hard, sometimes the car will just shut off

 

Have you had the alternator tested while it was in the car to see if it was sending a charge to the battery?

 

nope, not sure how to do that

 

A simple way for you to check it is to get the car cranked and use a digital multimeter set to volts DC and measure the voltage across the positive and negative post of the battery. Now have someone rev the engine to about 2000 RPM and watch the voltage readings on the multimeter. If the voltage reading go up to about 14.5 or 15 volts DC and stays steady then the alternator is charging the battery.

 

ok ill try that today, what about if it turns out to be not charging. any suggestions what i can do to fix it?

 

If it isn't charging, take the alternator to a auto parts store and have them test on their machine. If it tests good, then you need to start trouble shooting the wiring circuit in your car for bad connections, fusible links, or wires not connected.

 

another problem im having is the tail light wiring is all messed up. does anyone have a diagram possibly for it that shows which wire goes to the other

 

i tested the module that plugs into the alternator for volts when the key is turned, it reads 0. battery reads 11.0 so its definatly not charging. i dont even know where to start looking for bad wires

 

i fixed the alternator, turned out to be the one wire that goes tot he ignition, it was cut or burned. i ran a new wire to the fuse box and it seems the alternator is working fine.