battery issues.

[eighty3gresr]

So I just put a 350 in my buick t-type. I can't get the battery (brand new) to keep a charge. I will charge it and the car will run fine for about 10 minutes then it will run like crap. I checked all my wires, everything is correct and I brought my alternator to advanced to have them bench test it and it checked out.

Any other idea's why the battery isn't charging?

J-rod

 

[85 Cutlass Brougham]

Could be the ancient wiring in the car. I would check the battery while it was running to see if the voltage is dropping. It should increase when the car is running versus not running. If this is not the case, disconnect the positive battery cable and do a continuity test from the alternator post to the end of the battery cable. If this does not check out, test the wires individually. They use the starter post as their main serial bus, so you need to test from the alternator to the starter and from the starter to the battery.

 

[Phoenyx]

Make sure all your grounds are good. And also make sure they are all still on the car.

 

[custom442]

what type of alternator... 3 wire? got a picture or part number?

 

[eighty3gresr]

Ok so I spent five hours of my life yesterday tracking this thing down. I went over every ground possible to the motor every wire. Couldn't find a damn thing wrong!

Finally just threw on an alternator 108 amp alternator that I had laying around from an old police car. Needless to say the car ran beautifully.

Apparently Advanced Autoparts doesn't refund the five hours of life I spent under the hood when the tech didn't know how to bench test it properly! :x

 

[custom442]

Ok so I spent five hours of my life yesterday tracking this thing down. I went over every ground possible to the motor every wire. Couldn't find a damn thing wrong!

Finally just threw on an alternator 108 amp alternator that I had laying around from an old police car. Needless to say the car ran beautifully.

Apparently Advanced Autoparts doesn't refund the five hours of life I spent under the hood when the tech didn't know how to bench test it properly! :x

Well some 3 wires need a third voltage sensing wire, others don't. Even if you had a good internally regulated alternator, and hooked it up solely as a battery charger w/ one ignition and one hot wire, then it still could have problems charging. This is even more true if the wiring harness is old and intricate like on these cars.