01 Silverado Charging Issue

Background: 01 Silverado 5.3L V8, new battery and alternator, 150,000 miles, old alternator quit working.

After changing the alternator, I have noticed a charging problem. When I take off and traveling down the road at "cruising" speed, I have no problems (cruising speed being the top gear at whatever speed 55, 65, etc). The problem occurs when I am traveling up a hill or passing. When I press the pedal enough for the gear to shift and the rpm increases, my voltmeter starts to fluctuate. If I keep the rpm's up long enough it will pull the voltmeter down below 12 volts and then I get the warning light. As soon as the gear shifts back to the top gear the charging system returns to normal. Another verification that it is not just the charging indicator is that my headlights will dim.

Bad Alternator, loose connection???? Any other thoughts or similiar problems?

thanks

john

Background: 01 Silverado 5.3L V8, new battery and alternator, 150,000 miles, old alternator quit working.

After changing the alternator, I have noticed a charging problem. When I take off and traveling down the road at "cruising" speed, I have no problems (cruising speed being the top gear at whatever speed 55, 65, etc). The problem occurs when I am traveling up a hill or passing. When I press the pedal enough for the gear to shift and the rpm increases, my voltmeter starts to fluctuate. If I keep the rpm's up long enough it will pull the voltmeter down below 12 volts and then I get the warning light. As soon as the gear shifts back to the top gear the charging system returns to normal. Another verification that it is not just the charging indicator is that my headlights will dim.

Bad Alternator, loose connection???? Any other thoughts or similiar problems?

thanks

john

who installed this alternator? is this alternator the exact same rebuilt ,,or an aftermarket copy...?


when vehicle is stopped rev engine with a voltmeter measure and see if the voltage drops ....it should not vary very much...at 75 deg f temp...the voltage when engine is normal temp should be 13.25-13.75 volts..

make sure the belt is correct/tensioner and the condition is good....no cracks checking of rubber,,,shinny glazed look etc...

j cAT,
I performed the alternator installation. It is an aftermarket copy, but it is the second one. Both were installed in the parking lot of the local parts store. After installing the first one, it would not charge from the start. The parts store did their check on the alternator and deemed it wasn't charging and was a bad part. The second one installed and checked out ok, but has since started giving me problems I described earlier. I had the same thought on the belt being bad (which it was worn out). I replaced the belt, but that did not fix the problem. I will check with a voltmeter when I get a chance. I have considered trying to get an alternator from a salvage yard that would be original equipment (if I can find one).

thanks

john

j cAT,
I performed the alternator installation. It is an aftermarket copy, but it is the second one. Both were installed in the parking lot of the local parts store. After installing the first one, it would not charge from the start. The parts store did their check on the alternator and deemed it wasn't charging and was a bad part. The second one installed and checked out ok, but has since started giving me problems I described earlier. I had the same thought on the belt being bad (which it was worn out). I replaced the belt, but that did not fix the problem. I will check with a voltmeter when I get a chance. I have considered trying to get an alternator from a salvage yard that would be original equipment (if I can find one).

thanks

john

using a scrap yard original to troubleshoot this is a way to determine if the aftermarket new one's are faulty..this problem your having is not the same as when the original alternator failed...also the original failed at a normal use period...

what is the part # of the aftermarket alternators you have tried out ???