so tonight i was driving and the car started losing charge on everything, so my brother came and we jumped it once and it ran maybe a mile and then wouldnt hold a charge or jump start or anything. my question is would you guys think that it was the battery(which is not that old maybe like 8 months), the alternator, or do you think that the underdrive pulleys somehow caused it. i have ford motosport underdrive pullies. at idle the volt meter would drop a little when the lights and all were on but once you started driving it everything would be normal. any help would be appreciated since i have to take my truck and get it tomorrow out of the peoples yard that its in! Thanks again guys!

 

Sounds like the alternator. I had the same problem a while back.

 

same thing is wrong with my mustang. You need a bigger alternator like 130 amp. stock is 65 or 70 amp. And the under drive pullies makes the alternator pullie biger than the stock one. so it turns slower. Some people said turn up the idle a little like 800rpm or 1000rpm. But im going with the bigger alternator. hope that helps.

 

try and charge the battery start the car then unhook the positive battery cable if the engine cuts out its your alternator

 

thanks for the replies guys, hopefully ill be going to drag it home soon haha...so then i can test it and all and see if it is the alternator.