1997 Cadillac SLS Heater / A-C fan running - no air

MACVOX

MEMBER
1997 CADILLAC SLS
V8
FWD
AUTOMATIC
97,000 MILES

My heater fan recently burned out that I had insalled six months ago (used). Except for the loud noise it made when running, everything worked ok.
Last week it burned out and I had it replaced with another (used) fan. The loud running fan noise was still there, but this time, , no air is coming through any of the duct work - on any of the settings - upper, lower, defrost, etc. I hear the vent doors working somewhat, and feel a very miniscule amount of air (both a/c, and or heat) excaping the open vents, but that is itl. I checked the vacuum hoses and found one worn through by the canister under the battery.
I've checked the fuses, etc. Still no air.

I surmise that the fan is blocked / choked, yet running, and this may be what may be why it burned out again.

Please advise regarding the no air on any setting issue as well as the noice issue.

Thanks much.

1 Reply

FACTORYJACK

MECHANIC
4,159 POSTS

I assume you repaired the vacuum line under the battery for starters, I believe it is responsible for hvac functions. If it sounds like a vacuum that has had the hose blocked, then I would suggest it's plugged. Are you in an area that could possibly have rodents. They often take shelter in the HVAC case, and possibly had built a nest. You have a bit of visual access when you have the blower removed. I don't believe a door out of position would choke off airflow entirely. Air does recirculate through the rubber tube that is on the motor, that is to cool the motor. The air inlet is usually under the cowl vent panel, under the wipers. It could possibly be clogged with environmental debris causing a concern as well, but that takes alot of debris.