My heater would not reach a "hot" temperature when I tried it the first time this fall. Assuming it was the thermostat, I replaced it but that didn't help. The engine temp is running normal. Any ideas?

 

Is there any air that is coming out of the vents?

Might have a clogged or bad heater core if cold air is just coming out....

 

The flow is fine. The temp is warm.

 

So then the flow is warm, but not what it was then?

 

Yes, the flow is barely warm. I thought about the clog possibility, but the fluid I drained when replacing the thermostat (180 degree) was very clean.

 

If there a cable at all that could need adjusting?

Family members Matrix A/C was not cool enough and it was just a cable adjustment.

 

The cable for the temp control? I can hear the vent change, but perhaps it's not moving far enough.

 

I believe there is a TSB for this. Let me see if I can find it.

 

I was wrong. I was thinking of the TSB for the air conditioning system.

Did you check the heater valve? Does it move when you turn the temp. control dial? Did you check the heater control assembly? It seems like many of the heat problems come from one of the control cables coming uncliped, especially behind the glovebox.

 

I can tell that something is moving when I operate the temp control. I'll try to examine the heater valve movement (if I can find it). I removed the glovebox...and it's tight back there.