My mother owns a 1992 Cadillac Deville with a 4.9. The vehicle will not blow hot air. The blend door moves appropriately. I replaced the thermostat. The AC compressor seems to operate continuously, even when set at the highest possible temperature. Is the most likely scenario a plugged heater core? Any thoughts? Thank you.


(This post was edited by Chef Jeff on Mar 10, 2008, 4:42 PM)

There are a inlet line and a outlet line at the firewall to the heatercore, feel the hoses, both should feel about same temp,if theres a noticable difference more than likely its the core,other signs include air in the system,waterpump, and the thermostat installed wrong way,bad temp switch

Replaced the core with great results. Thanks for the input.

Glad it helped,just post your auto problems and we'll do all we can to help

"ATTA BOY DAVE"!!!!!!

Thanks Jim , I needed some encouragement after that van deal