Squeaky Silverado

I have a 2005 Silverado. When I turn on the heat/a/c, it starts to squeak. The squeak seems to be affected by going over bumps or rough roads. It also seems to stop if I turn the fan all the way up. Also, it does not squeak when I turn the fan off.

The squeak is coming from under the dash board on the passenger side.

I appreciate any help.

This sounds like a simple case of a noisy blower motor. Yhe location is right,the fact that it goes away when on high fits perfectly,the fact that it is not present when off fits,what else do you need to tell you your blower motor is noisy?

The squeak might be coming from a worn blower motor shaft bushing. At the lower blower speeds the bushing may worn to where when bumps are encountered, it causes the blower motor shaft to position itself on the worn bushing to where it starts to squeak. At the high blower speed the noise doesn’t occur.

Tester

That’s what I figured. I am just wondering how far back it is, and if anyone knows what the proceedure is for replacing it. Or more important, is there anything I need to look out for when I replace it.
Thanks

You need a new blower motor if you remove it and find no debris interfering with it. You can probably change it yourself. You can probably see it when you look under the glove compartment. Mine is there on an 02.