I'm stumped guys. The batt./alt. light keeps coming on while driving. The voltage regulator reads normal at approx. 14vdc. Seems to happen when I let it idle for more that a few minutes or when I play with the climate controls while driving. So far I have replaced the alternator, cleaned the chassis ground, cleaned the battery terminals, checked all cables and fuses to include the alt. mega fuse, replaced the dash bulb, and used the mutlimeter to verify all voltages are proper. I replaced the alt. 3 months ago when it failed while I was driving and everything worked well since then. Now the light comes on, but that seems to be the only symptom. Any ideas?

 

Check the condition of the belt and tensioner. If the tensioner is bad it won't keep the belt tight enough and may slip.

 

I have a new belt, but question the tensioner. According to the manual, you basically tighten it to the proper direction (maybe left hand, but do not remember) until it stops. There was no torque so I just tightened it. I have been working on aircraft for years so whenever I have to tighten something without a torque value, I always wonder. I will take apart the tensioner and clean, lubricate and reassemble it. Hopefully that will do it because I am at a loss. Thanks for the reply though. Will keep you posted.

 

Cool, let us know. My tensioner is spring loaded, no tightening is needed. I thought all were like that but I don't know if the newer trucks are different.

 

Ok so I checked the tensioner and it was loose. I guess there was some corrosion or gunk built up that kept it from retracting fully to the tight position. Cleaned and lubed and she works fine again. No light for the past few days. Thanks Sean

 

Your welcome. Cheap and easy fix, I like those.

 

dang that sucks that you bought all of those replacement parts..

 

Replacing those parts was not so bad mbrown29. the alternator was the only part that cost much and with the core charge it was not bad. With the mileage on my ride I feel better knowing it has been replaced anyway. I'm glad I did not have to replace it on the side of the road in February when it's freezing cold. Sometimes a little piece is worth the money.