Alternator

[TheGambler]

Well I just got a new battery for my ride. On the way to get the battery the battery gauge was reading 16 volts the whole way to the ATM. I stop to get money out to pay for the new battery. as I am sitting there getting money out of the ATM. my gauge drops down to 10-12 area. I have to use the gas pedal to keep it from dieing. I then make it to the auto parts store and get the new battery. i was driving down the road later and the head lights dim and the gauge drops below 14 volts for a second. Autozone said the alternator was fine, It was putting out 14 volts. well I told them that my truck runs usually above or at 15 volts on gauge. I am wondering if my regulator is going bad on my alternator.by the way the only thing I was running was the heater at 1 and driving lights. no radio

If so (by the way spent all my money on the new battery, I hate minimum wage but what can you do) is there a rebuild kit for it or just buy a new one?? how big? I run a trailer every once in a while last time I was hauling at night with high beams and radio it head lights dim down a couple times.

 

[Playsinsnow]

It's normal to have the volts drop a little drving is slowed to idle. I would put a meter on it when it is parked. What does it read at the battery at idle? Does it drop when you increase the load? i.e. turn heat, radio, and highs on? That to me is the tell tale sign of pending failure.if it drops from 14.6 or whatever to 14.2 then to 13.x without getting back up.

These things are weird with the SAIS and everything else going on. Put a meter on it and test it?

 

[JerryIrons]

I second putting a meter on it to verify, they aren't that expensive and are super handy to have for general troubleshooting. btw running 16 volts on your battery isn't healthy for it, it's too much and will shorten it's life.

 

[C-ya]

I have a 145 A alternator on mine. Spec'd in the RPO codes. KG3 = 145 A. I'm not sure if there would be any problem putting a higher output alt on a vehicle that had a lower output originally, but I doubt it would be a problem. The alt only outputs what is demanded of it, but having more on tap is not a bad thing.

 

[BoldAdventure]

I have a 145 A alternator on mine. Spec'd in the RPO codes. KG3 = 145 A. I'm not sure if there would be any problem putting a higher output alt on a vehicle that had a lower output originally, but I doubt it would be a problem. The alt only outputs what is demanded of it, but having more on tap is not a bad thing.

According to The Roadie the high output alternator is a myth and they're all 145 amps, on all GMT's.

I am planning on installing a DB Electrical 250 amp alternator specific for our platform:DB Electrical - ALTERNATOR HIGH OUTPUT 250 Amp 4.2L TRAILBLAZER 02 03 04 05 ENVOY

 

[davenay67]

Well I just got a new battery for my ride. On the way to get the battery the battery gauge was reading 16 volts the whole way to the ATM. I stop to get money out to pay for the new battery. as I am sitting there getting money out of the ATM. my gauge drops down to 10-12 area. I have to use the gas pedal to keep it from dieing. I then make it to the auto parts store and get the new battery. i was driving down the road later and the head lights dim and the gauge drops below 14 volts for a second. Autozone said the alternator was fine, It was putting out 14 volts. well I told them that my truck runs usually above or at 15 volts on gauge. I am wondering if my regulator is going bad on my alternator.by the way the only thing I was running was the heater at 1 and driving lights. no radio

If so (by the way spent all my money on the new battery, I hate minimum wage but what can you do) is there a rebuild kit for it or just buy a new one?? how big? I run a trailer every once in a while last time I was hauling at night with high beams and radio it head lights dim down a couple times.

Last year I was experiencing somewhat similar electrical issues. Things would seem OK one moment and then not be quite right on another. I suspected the battery the place that sold it (Interstate) tested it and recommended a new one. It was under partial warrantry and the new one was much cheaper as a result. This seemed OK for a very short while, but then it started to behave like before. I now suspected the alternator and began to run all the electrical tests I could, none of which provided me the conclusinve evidence I was looking for. So I bit the bullet and replaced the alternator anyway, and everything has been perfect ever since.

Not saying yours in the same issue by any means, but be prepared to suspect the alternator (or the alternator wiring) if a new battery doesn't help. Could also possibly be the battery cables too. Quite a few things to check in the electrical charging system.