i have a 1989 cadillac brougham 305 or 307 v-8 to where the alternator belt started squealing. i was told the alt was bad (13 volts) so i replaced it and the belt. the new alt does the same thing except now after after a few minutes the squealing noise goes away and the alt charges as normal (14 volts). now if i turn on the headlights the noise comes back until i turn them off. the auto parts guys says the alt is good and there is another issue. what else is in the charging system that would put a stress on the alt to make it sound like the belt is bad. the alt uses a v belt and is the only pulley using this belt. what other component can put this kind of stress on the system. im at my whits end. thanks

 

by the way the a/c belt has been off of the vehicle for a year or so. would this have some kind of effect on how the alt work? i do remember the a/c clutch cycling on and off years ago when the belt was on the car. since the a/c did not work i never replaced the belt when it broke

 

stupid question but did you change the belt or the alt?

only seeking clarification as you mention alt and belt at the one after the other

"where the alternator belt started squealing. i was told the alt was bad (13 volts) so i replaced it and the belt. the new alt does the same "

 

scrap that, read the sentence for the 20th time and got it through my thick head.

do you have the right sort of tension on this belt? sounds like its loose enough to squeal and then when it heats up it stops.

 

thanks for responding. i've cranked the thing pretty tight to where i thought i'd break the belt. i was afraid to leave it tight as it might damage the bearings after awhile. i even cleaned the pulleys before putting everything back together. this thing has me scratching my head and 2nd guessing everything i did to put it together

 

can you get a pic of the routing of the belts, ive googled it and come up with half a dozen different interpretations of what the setup it

 

Yeah, I'm with Zed. Sounds like an adjustment problem.
Try that first
Oops, slow typing and not keeping up.

 

It sounds like he's running a v-belt... If that's the case, it's pretty tough to mess up the routing.

To me it sounds like there's too much load on the alternator, as evidenced by it starting to squeal again when he turns on the headlamps.

 

Could be a worn pulley, either on the alternator or the crankshaft. If the sides are worn, the center will be contacting the bottom of the groove and it won't get good grip on the sides of the V.

 

i just figured out how to load pictures (dont laugh) the alt pulley is all by itself on the one belt.

 

the empty pulley on the water pump goes to the a/c but the a/c belt broke a year ago and i never replaced it since it did not work

 

 

this is the left side of the motor. the a/c (minus its belt) and the air pump

 

i hope you guys dont mind this many pictures and i appreciate you just looking things over for me. i've never been on this kind of a website before and i've already been reading so many articles on so many different things. even if we dont figure out this belt thing im already ahead on other things. so thanks for your time

 

i just rechecked the voltage at the alternator while it was running and squealing and it was 14. after about 5 minutes the noise stopped and the voltage went up to 16. i disconnected the battery and its voltage was 16 also.

 

dunno if its the photo, but does anyone else see an alignment issue in the last pic?

 

hi zed 028,
the picture is kind of curved. its like and illusion but to make sure i went out and looked at it again to make sure it was straight and it is.

i just spoke with a tech at the alternator factory and he said that the motor in my cadi is an oldsmobile motor and if i tighten up the power steering belt really tight i should get rid of the squealing. something about the power steering pump pulling down the whole system. i've heard stranger things and if i get a chance tomorrow i'll give it a shot. its raining here in columbus ohio. maybe this is like an ancient chinese secret. at this point i dont know what else to do. the tech even said that on some cars like mine that the power steering pump and alternator should share the same belt. who knows

 

It looks like the AC belt is supposed to go around both the crank and water pump pulleys. But the alternator belt only goes around the water pump pulley. So the belt that is squealing is probably the power steering belt trying to run the water pump, power steering pump, and alternator all by itself without assistance from the AC belt. The extra load on the alternator when you turn the lights on is the straw that breaks the poor camel's back.

But, this is a 3rd gen f-body forum; not more than one or two Cadillac or Olds engines in 3rd gens that I've ever seen. So, we'll say "goodbye" to this thread now.