Alternator issues

[nclatino]

I replace alternator and battery , voltage at 12.85 when off and 14.45 when running but as soon I turn lights on rpms drops alternator belt squeak and alternator stops charging if I disconnect alternator plug rpms go up like is has no load and voltage goes up again .. I rewire it and same thing happened. Any ideas ??

 

[SirRobyn0]

I replace alternator and battery , voltage at 12.85 when off and 14.45 when running but as soon I turn lights on rpms drops alternator belt squeak and alternator stops charging if I disconnect alternator plug rpms go up like is has no load and voltage goes up again .. I rewire it and same thing happened. Any ideas ??

Well it sounds like the belt is too loose. That's the main cause of a V-belt squealing underload. If the tension is good and the pullies are in alignment, then it could be that the alternator is putting to much drag on the belt, in that case it would be a defective alternator. Even new parts can be bad and if you picked a remaned alternator then it has a greater chance of being bad especially if it a cardone, or store branded cardone, such as NAPA. Though ACDelco remaned alternators seem to be pretty good.

Why was the old alternator replaced? If it was replaced for the same problem you have now then I'd look at other possible issues, but if it wasn't doing this before the alternator replacement and the belt is in good condition and tight I'd be getting that alternator warrantied. If you bought a reman unit, most parts stores will upgrade you to a new unit (if you pay the difference in cost).

 

[Grit dog]

Yes, the most likely cause is a defective reman alternator.
It’s fairly common.

 

[SirRobyn0]

Yes, the most likely cause is a defective reman alternator.
It’s fairly common.

No offence to the OP, but as I wrote that out I felt like a broken record regarding the reman thing....

 

[Grit dog]

No offence to the OP, but as I wrote that out I felt like a broken record regarding the reman thing....

Yeah but it’s all good. Alot of people wouldn’t know that if they don’t buy or replace alot of parts. (Unlike you, lol)
And moreso, generally one would expect if they bought a new part or component that IT would not be the cause of another or a continuing issue.

 

[nclatino]

Well it sounds like the belt is too loose. That's the main cause of a V-belt squealing underload. If the tension is good and the pullies are in alignment, then it could be that the alternator is putting to much drag on the belt, in that case it would be a defective alternator. Even new parts can be bad and if you picked a remaned alternator then it has a greater chance of being bad especially if it a cardone, or store branded cardone, such as NAPA. Though ACDelco remaned alternators seem to be pretty good.

Why was the old alternator replaced? If it was replaced for the same problem you have now then I'd look at other possible issues, but if it wasn't doing this before the alternator replacement and the belt is in good condition and tight I'd be getting that alternator warrantied. If you bought a reman unit, most parts stores will upgrade you to a new unit (if you pay the difference in cost).

Old alternator was replace for not charging battery. This is the second alternator I replace because the first one was bad as you said , the weird part which don’t make send to me is that if I disconnect the alternator plug a few times and plug it back in squeaking goes away alternator charges and everything seen fine but if I turn lights on again I get the same result

 

[SirRobyn0]

Old alternator was replace for not charging battery. This is the second alternator I replace because the first one was bad as you said , the weird part which don’t make send to me is that if I disconnect the alternator plug a few times and plug it back in squeaking goes away alternator charges and everything seen fine but if I turn lights on again I get the same result

That might seem weird but it's really not. It's all about load. When that plug is disconnected the load on the alternator and therefore the resistance to turn the pulley is low. When it's plugged in the alternator is working to charge the battery and the load is increased on the pulley therefore causing the belt to squeal. An internal problem in the alternator can increase that load. If the belt is in good shape get the alternator warrantied.

If your still not sure feel free to post pictures of the alternator and belt, also a video of the truck running and acting up. But seriously doubt any of that is necessary, just go get that alternator replaced under warranty. Upgrade to new if you bought reman.

 

[SirRobyn0]

Yeah but it’s all good. Alot of people wouldn’t know that if they don’t buy or replace alot of parts. (Unlike you, lol)
And moreso, generally one would expect if they bought a new part or component that IT would not be the cause of another or a continuing issue.

Right, one would think a new or remaned part would be good, but it's all about failure rates. A new ACDelco alternator might have a failure rate of less than 2% units where a remaned cardone unit might be around the 15% mark, sure 85% under those figures 85% of cardone units at least make it out of the warranty period....

 

[Ontheboulder]

you might try replacing the belt,sometimes they get worn in to a certain pulley but start making noise with a new one

 

[nclatino]

I replace the belt .. squeaking is gone until I put some load..

 

[Ricko1966]

I replace the belt .. squeaking is gone until I put some load..

Tighten the belt some more.

 

[nclatino]

Will try next

 

[vintovka]

Yes, the most likely cause is a defective reman alternator.
It’s fairly common.

This is true of almost all remanufactured parts today so heads up. Recently Had a 2 NAPA reman power steering pumps fail in rapid order. (84 GMC). Last one nearly resulted in a fatal accident. Alternator belt tension is critical and readjustment is recommended as needed.

 

[SirRobyn0]

This is true of almost all remanufactured parts today so heads up. Recently Had a 2 NAPA reman power steering pumps fail in rapid order. (84 GMC). Last one nearly resulted in a fatal accident. Alternator belt tension is critical and readjustment is recommended as needed.

I just called my contact at NAPA not surprisingly NAPA reman'ed power steering pumps for our trucks are remanufactured by Cardone industries....

 

[nclatino]

I got another alternator bigger amps will put it sometime this week