I know it's July and it's 90 out....but my MSM's cabin heater isn't working. The fan comes on nicely, blowing lots of cool air....Unfortunately, the A/C isn't on!


I've cleaned out the cabin air intake (under the cowl on the passenger side), with little effect, although the fan probably appreciates the lower resistance.


The radiator is full of water, and hasn't leaked a drop in the 3 months since the last coolant change. The water temp, per the real water gauge is around 205 deg F typically at low speeds, 190 deg. F at higher speeds.


The two heater hoses at the firewall are both hot when I set the fans to high and the heater switch to max heat. Just nothing comes out of the vents but cool air.


I'm going to try changing out the thermostat, on the theory that it failed open. That however, feels like simply throwing parts at the car.


Any thoughts as to what I'm missing....other than heat!! Or any other diagnostic tests I can try?

 

Below the glovebox on the passenger side of the center console there is a little cable that operates the mixing door that adjusts the temperature. Make sure it is connected and moves when you adjust the temp control lever. If it doesn't move it may be disconnected on the other end behind the A/C control panel.

 

Thanks. I'll try that.