Bought a used Tahoe. I noticed whent I opened the engine compartment that the duct for the blower had pulled apart. Easy fix, right? Not so much. I couldn't immediately find any plastic 4" duct so I used duct tape as a temporary fix. TO MY SURPRISE, after I get it all taped up and close up the holes the blower motor is BACKWARDS! It's sucking air into the engine compartment instead of "blowing" the air out of the engine compartment. Needless to say I reversed it. I'm assuming the previous owner "fixed it" but really had no idea what he was doing. SCARY! Air output from the engine compartment is pretty stout now!