Alternator squeal

mbalbritton

mbalbritton

#@$%!
Joined
Mar 22, 2005
Location
Lakeland, FL
So I've been wrestling with alternator, belt and water pump issues (all on the same belt). About the time I think I have it all squared away, I'm now getting squealing from the alternator/belt.

If it's cold and or wet it's worse. Lights, heater and wipers running and it'll squeal like Ned Batty on a camping trip. I have to turn off my heater and wipers when pulling away from a stop light.

I put on a bigger GM 1 wire alternator so it's pushing more juice. But to be honest, I don't know much about vehicle electronics, so I don't know the cause. Is the squeal the alternator or the belt slipping? Could marginal wiring connections be the culprit? Give me a crash course.
 
What condition is the belt in? Does it squeal all the time? Have you tried replacing it with a new one? It could be a number of things. From my experiences, it could be:

- a bad belt
- a bad pulley/bearings
- not enough tension on the belt
 
If everything is in good shape, then the only ways it could slip are the belt is not tight enough, or the alternator does not turn freely enough. If there is a ton of load on the alternator or something wrong with the alternator, it would not turn freely and the belt would squeal. But regular operation of the vehicle shouldn't cause that. Sounds like a tension issue. Is it a self tensioner or adjustable?
 
Is it a v or multi rib (serpentine). And what amp alternator. Once you get above 70 amps v belts start slipping at full charge. I converted my 78 f150 alternator to multi rib belt when I went to the ford 130a alt from a taurus. You may have to do the same or run two v belts if possible.
Make sure the belt runs true too. If it pulls at a slight angle it will squeal like hell.
Also run a good quality belt. The cheaper line belts stretch constantly and you can't keep them tight. A good belt you can slap on run for ten minutes then retension if its not self adjusting.

Sent from my XT907 using Tapatalk
 
V-belt, adjustable tension, and I honestly don't recall what amp the Alternator runs. I was thinking 90amp, I don't recall if it's a 10si or a 12 si, I'll have to go look, and it came with a V belt pulley. Belts are inline and true. The Belt is the Higher quality (pricer) one from the parts store.

I'll check which Alternator and check the tension. I've heard different theories about belt tension. Too tight and you'll wear out the bearings on your water pump, too loose and belt squeal. I've heard anywhere from 0.5" - 1" wiggle in belt on the longest run between pulleys. 1" seems like too loose to me.
 
Too tight does put more wear on all the bearings (water pump, alternator, and even the front crank bearing) but I'd definitely run it tighter than that. The .5-1" span is a general guide and I've usually heard lots for a 12-18" span between pulleys. I'd tighten the belt up and see if you can get the squeal out without the belt being as tight as a banjo string.

Sent from my XT907 using Tapatalk
 
does the V belt ride high on the pulley ( slightly proud of the groove ) or does the belt rest below the top of the V on the pulley(s) ?

A V belt grips on the sides, if the belt isn't wide enough ( or the pulley is worn that much ) the belt rides low in the groove and bottoms in the V, there is no grip there and the belt will slip, which is the squeal you're hearing.
 
Yea just replace the belts or give it about a week and then it should go away but if it dosent the belt is prob bad
 
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