Hello I have a 89 RS 305 TBI. I have been having issues with it the past few days. I've changed out the Oil Pressure Sensor and the alternator. My car will not start unless it is jumped. When my car is jumped it will start and run fine for about 3 minutes but then it will suddenly start to sputter and then quit. The battery is also new and has no issues. The lights dim and eventually stop working even though the car is running. The turns signals slow to the point to where the lights are just on. Then when the car dies, the car will not start because the battery is dead. This has gotten very frustrating. Please somebody help me! It's my only car and really need it to be working.

 

It may be a charging problem. If it's not charging it will jump start and run but will die soon after when you take off the cables and no longer have 12 volts in the bat. Check to see if your alt. Is putting out over 12 volts if not its most likely bad. Leave the jumper cables on for a bit and see if it still dies. If it keeps running with the cables on then it is a charging problem. If you can't test it take it to a auto parts store and they will check it for you. Hope this helps

 

Yes that's exactly what it does when I take the cables off.

 

Definitely sounds like a charging problem. Check all connections particularly the big red wire from the alternator to the battery. Either that or they gave you a bad alternator. Have them check it and replace it if needed

 

Would it be possible to make a cheater wire from the back of the alternator straight to the battery to make it work temporarily assuming nothing is wrong with either the battery or the alternator? Or would that be a bad idea?

 

Ok so I figured out what it was. Just needed to get the battery charged at auto zone completely. Apparently when the battery is deader than dead the altinator won't even try to charge it. Now the car is running just fine! Thanks!