Expert: autohelp - 1/21/2009

Question
I have a 2000 Cadillac Deville with no heat.  When driving one can feel heat and can feel the AC kick on when the temperature is set appropriately.

The issue is intermittent.  The Fan will engage when the temperature isn't extreme -- when you don't need it.  Also, sometimes if you hit a speed bump just right it will engage also.

The Fan has been replaced by the dealer by the previous owner within the past year.  They didn't take it back before I got the car.

Any ideas of what could cause an intermittent heater fan issue?

Answer
IS or HAS the CHECK ENGINE light on the dash ever illuminated or have you seen any messages in the message center display ?.

You most likely have a fault with the INSTRUMENT PANEL INTEGRATION MODULE, BLOWER CONTROL MODULE or an intermittent faulty GROUND.

You will need several pictures of component locations and directives to perform simple test procedures using a DIGITAL VOLT/OHM meter which you can purchase at most any auto parts store for about $15.00.

Since this website, which is not mine only allows ONE picture you will need to E-mail: onlineautohelp@msn.com