My charging system charges sometimes and other time doesnt- i replaced the alternator, ran a new ground to the motor, replaced both battery term. ive wiggled,shock every wire on that system-nothing. Any ideas? thanks Lin

 

What are your symptoms? How do you know it's not charging?

 

I put a voltmeter on the battery sometimes about 12.4 volts othertimes 14.2

 

Does it do this rapidly or do you notice the lights are dim for a period of time so you go out and check the voltage?

If it does it rapidly or with a pulsing action, were do you have the ground wire from the battery hooked on the engine? The reason I ask is we had a problem that took a poster a while to figure out. He finally found out he was hooking the ground wire to an aluminum bracket on the engine, which did not have a good connection to the engine block.

P.S. Do you have a late model truck that has the alternator/regulator wire going to the engine computer?

 

Never trust your eyes -the harmonic blancer and the bottom belt pulley are one unit on this model it is sandwiched together with rubber -one part is bolted to the crank and the other piece drive the belts. The rubber came apart on one piece, even though it looked ok and allowed the two pieces to turn at different speeds. So the alt. looked as if it was turning was turning at a reduced rate sometimes and fast enough to charge other times. It finally came completely apart or i would still be guessing...

 

Was engine above or below 850 RPM at the time of testing?

The VR doesn't kick in until about 825 RPM

"At Idle" is not really a time to check charging.

I hope you didn't remove a battery cable with engine running

 

Glad you got it fixed, that was a tough one.

 

Thanks Dave....