99 GMC Yukon no heat **SOLVED

[Fless]

The pic is a bit blurry but is that meltage (made-up word) around that pin?

 

[the 18th letter]

The pic is a bit blurry but is that meltage (made-up word) around that pin?

View attachment 447746

Yup. I cleaned it up and it’s working for now. I tried to switch the connection from the aftermarket but the knob pin goes all the way on the aftermarket, but not on the OEM.

 

[GMCChevy]

I went for a ride today and I can hear the mechanism moving in the dash when I set temp from hot to cold and back. In addition, the air was see your breath cold with the temp set to cold. I felt the upper and lower radiator hoses and the uppers warmer than the lower. There’s a coolant leak as the reservoir was empty but radiator was still pretty much full.

Did you check the rad hoses or heater hoses? Rad hoses should have a difference like that the heater hoses shouldn't be as noticeable but both should be warm.

 

[the 18th letter]

Did you check the rad hoses or heater hoses? Rad hoses should have a difference like that the heater hoses shouldn't be as noticeable but both should be warm.

I did not since cleaning the connection on the old switch resolved the issue and got the heat hot again.