2004 Excursion with a 5.4L. Wife calls, says heater isn't working. I figure heater valve is dead, pop the hood, check connections and get ready to buy a replacement.

But my hand grazed the A/C line on the way out and it's ice cold & covered in condensation.

A/C is turned off (front and rear zones). Manual controls.

Why is the compressor running when it's shut off? I MAY have heater issues here (i.e., blend door, heater valve, etc.) but I suspect that the heater valve is being told to stay shut since the A/C is on.

Help?

 

Bueller? Bueller?

 

I'm not sure about your 2004 but the owners manual for my 2000 7.3 states that any time the selector **** is turned to a spot that has two options such as the dash/floor or defrost/floor as well well as the Max AC and AC and Defrost the AC compressor well run. I have unplugged the connector (easy to spot right on the AC compressor) that engages the AC compressor for a couple of months during the winter without any ill effects.

 

Interesting. I don't have an owners manual (2nd owner) so I'll change the selector settings and see if the heater hoses ever get hot at all, and whether the A/C compressor stops running. Thank you for the input.