when heater controls go on it makes a lot of noise...what is this?

[Oaktown]

when i turn on the heater/defroster/ac controls it makes a lot of noise...im guessing it is the motor but i am not sure. This is my second 87 with this problem. Its so loud that id rather be cold then to have to listen to my heater growlin...anyone else had this problem? what is it? how do you fix it? thanks!

 

[JESTER]

PUll the fan motor out. It's under the hood, on top of the heater box. I think it's six, 9/32 hex screws, but they may be 5/16. Look down inside the fan plenum, there are probably a bunch of leaves and crap in there. I had a bunch of leaves in mine that hit the fan wheel and made a hell of a racket. Same principle as a baseball card in a bicycle spoke. If nothing is hitting the fan wheel then it may be the motor, It's easier to look for obstructions before buying a new fan motor. Hope this helps.

Eric

 

[kh440]

I would agree w/jester about debris in the cowl. A fan motor going bad will usually give that didtinct burning smell when it's getting ready to crap out. (USUALLY) Once you have removed the motor spin it over by hand and look for any excessive wobbling, or if it spins freely.