So this Saturday I changed the water pump and the serpentine belt that turns the water pump on my wife's 06 xa. Everything went well until now. Whenever the ac is turned on it makes a horrible screeching noise. What did I do wrong?
I already tried making the belt tighter this didn't work. Any suggestions?

 

May be the belt got some coolant on it so it's slippery? Other than that may wanna try just replacing it. You def don't want to make the belt too tight– that will ruin the pump's bearing very soon.

 

I did replace it. It's a new belt. Still making the screeching noise. Weird why it would do it only when the ac is on. Any other suggestions?

 

Could have something to do with the clutch on the ac compressor. or the compressor itself!

 

What brand? I personally have complete trust only in the OEM Mitsuboshi belts, may be Gatorbacks too.

 

It's a Toyota oem belt. I removed it today and it looked fine. There was no noise before I changed the pump and belt. I did notice that when I changed the water pump I push the alternator into a hose coming up from the ac compressor and it is now a little bent to the side. Also when pouring in the coolant I might have spilled some on the ac compressor/pulley/belt. Any other suggestions?

 

So I just took the car for a ride. When the car is first turned on and you turn on the ac before moving the loud screeching noise comes out. This happens whether ac is low or high. Once you start driving the noise completely goes away. When you're coming to a stop the noise only starts again if ac is on high. It can be 3/4 maximum and noise only comes on until you put it in high. Any help?

 

Bad tensioner? It sounds like it's slipping on the pulley. Once it warms up maybe it's gripping a little more?

Sent from my SCH-I535 using Tapatalk 2

 

It was the belt slipping, thank you all. That belt has to be on very tight. Pulling on the alternator wasn't doing i had to stick a screw Driver in there and pull hard.