Loud AC/Heater Fan

[Chinookers]

The cab AC/heater fan has suddenly become much louder - a much deeper guttural sound - especially on maximum.

It's significantly louder than it used to be - on all the setitngs - AC, vent or floor / mix. The AC and heater still work fine - just that the fan all of a sudden became much louder.

Not sure if something has got in the fan or the duct, or maybe something has come loose. Any thoughts? Could a critter have got in there? Anyone experienced something similar?

Appreciate any wisdom you can share.

[chin_k]

Mine was alright, until one day the entire fan motor came off, make loud noise for a few minutes, then the blades got caught on one of the corners, and stopped the motor completely. I thought, wow, the fan got nice and quiet all of a sudden!

[ASaucyBurrito]

Not exactly the same scenario, but my 1993 has been making squeaking noises at speeds 1-3 since we bought it. Recently purchased a replacement fan/motor that should arrive this week for $35 from RockAuto. Hopefully that eliminates all our issues.

I do think these are prone to various failures from prior research.

[ASaucyBurrito]

I changed out my fan last night. The bearings in the motor appeared to have been failing as it had significantly more friction than the unit that replaced it. I could also hear a whining/grinding noise, even when spun slowly by hand, that has been noticeable in the cab since we bought the rig.

Change is very easy. I have a 1993 with the coach battery in the engine bay so that has to come out first. After that the assemblyt comes out with four hex head screws and the electrical connector.

Before


After


I purchased TYC 700087 from RockAuto for $33. If you do end up changing it, you'll have to look up the specific fan for your model as I believe the connectors changed slightly over the years. TYC brand has been good to me in the past.

Good luck!

[Chinookers]

Thanks so much - very helpful