S-10, v-6, vortec engine, alternator, 1996 model

Qamar · Post by **Qamar** » Wed Jun 22, 2005 1:15 pm

The alternator of my subject truck is passing 12.2 Volts with AC/ Head lights on, witout that it goes to 12.3 volts. Anyone who could tell that is it fine or the alternator is dying slowly.
My observation is that the dash lights during night time now appear to be little bit low, and the voltage gauge in the dash board has also gone down, ie in between the first white line to 14. However when i race up the engine it slightly moves up but never touches the mark of 14.

Should i change the alternator or let it move like that?

Thanking in advance

barch97 · Post by **barch97** » Wed Jun 22, 2005 1:54 pm

I never actually measured it that precisely but had experienced similar symptoms prior to replacing my old worn out and significantly stretched serpentine belt. I don't mean to through you off the path of the aged alternator but, check the belt and electrical connections at alternator and battery first.

Qamar · Post by **Qamar** » Wed Jun 22, 2005 1:58 pm

Ok i will first of all check the connections of the battery and the alternator. Well can you guide me as how to tighten the serpintine belt? Is it done through the adjuster bearing sort of thing?

Regards

Post by **HenryJ** » Wed Jun 22, 2005 3:24 pm

The belt on these receives it's tension from the tensioner/pulley assembly. There is no adjustment. You will need to replace the belt if it is glazed, and or cracking.

The alternator should put out 14.3 volts cold, and as little as 13.5 hot. If you have more than 80,000 miles on it (not sure of the conversion to Km) , you need new brushes, and probably bearings.

Battery condition is critical. A bad battery will take out an alternator in a hurry. Think of the battery as a cushion. It softens the blow when there is a big jump. If the battery is bad the alternator is not only working to hard and building heat , but it is being beat on too.

Qamar · Post by **Qamar** » Thu Jun 23, 2005 4:22 am

The Alternator while cold is putting out 13.5 and when hot with with load of AC and head lights is giving 12.2 or 12.3. So do i need to get it opened and change the brushes in it? The bearing appears to be fine. The truck has done 87000 Km only.