Cadillac Repair: 89 sedan deville heater not hot, floor vents, thermastat

Question
Hi Tom, my buddy has the 89 sedan deville and he says the heat is not getting hot.  Just a little bit of warmth.  He has replaced the thermastat and heating coil.  He said he has hardwired the blower motor but it still won't get hot.  Can you think of anything it might be?  Thanks alot

Answer
Could be the AC/Heater programmer.

1. Open the glove box and remove the glove box liner.

2. Look into the glove box area and see if you can see a short metal threaded rod snapped into a plastic retainer.

3. Mark the rod at the plastic retainer so you know exactly how to put it back in the same place.

4. Unsnap the metal threaded rod from the retainer and with your heater set to maximum heat, Pull the threaded rod towards you and see if you get any heat out of the floor vents and a small amount out of the defrosters.

5. Snap the rod back in the retainer where you marked it.