Battery light

My battery light comes on intermitantly. It goes off when I punch the throttle and get the revs up. Belt is tight and the connections are clean. The alternator is from Autozone and about 3 years old. Any ideas?

 

Put a volt meter on and see what the voltage is at idle.

Could be your electrical load at idle is exceeding what is in your system.

Battery getting old ??

 

Have the alt tested, then check your connections. You should have the same reading at the alt itself as at the battery. Unless you're pulling a ton of amps (stereo equipment etc) you're running solely on alt power while the truck is running. Most times a bad ground or other connection problem is your culprit.

 

Alt and battery tested good. If it happens again, I'll put a new alt on. Mechanic said it's probably a short in the alt.