Rep Power: 0

Yes I've searched about this...

2003 4dr Ex

So I was driving the other day; heat working fine (around 25f outside). Suddenly I started to get HOT; I thought it was just sun beating in, so I turned it over to cool. When I turned it back toward warm, there was no response at first until I turned it all the way to hot. This happened again later but after turning it to cool i never had heat again.

I suspect the air mix selector door has gotten jammed or the temp dial isn't working. I don't even know where it is to try looking at it. When I turn the vent selector, I can hear a faint servo motor running, but no sound at all when turning the temp selector. I had a look at the harness behind the radio and it looks OK but way to complex to test without a wiring diagram.

I checked the coolant lines and near the radiator at least they seem warm. I know everyone says thermostat and coolant level when you post about heat problems, but believe me it went from working perfectly to Not at All while I was driving. And yes I checked the coolant level, it's fine in both the bottle and the radiator. There is absolutely zero heat now

Can anyone with a service manual shed any light on where to look for this? I'm probably just going to take it to the stealership this week.

 
Rep Power: 307

The manual shows the "heater valve" under the hood near the supply and return line for the heater core. I would try to get a look at this to see if arm on valve is moving when you turn the heat **** back and forth.

 
Rep Power: 0

Thanks, I'll have a look

 
Rep Power: 307

I looked at my 05 this morning the valve is visible with a good flashlight.

With the car running have someone run the heat control back and forth while you look to see if the arm and attached cable moves.

 
Rep Power: 0

Well after poking around under the dash for a while figuring out where all the parts and motors to the system are, I discovered a loose connector on the motor that operates the air mix door and heater core valve. Just plugged it back in and it worked!

 
Rep Power: 241

hrmmm and where is this connector haha?