2nd Gen Non-Engine/Transmission Temperature controller, HOT only!!!!! Help

[johncameron]

After changing my heater core the temperature controller doesn't work and I only get heat!!



Is that control vaccum or electric?



Is there anything easy to check?



THanks in advance!



John

 

[DLausche]

Man, I wish I had that problem. I haven't had heat in my truck for several years now.



I am pretty sure all of the heater/AC air controls are operated by vacuum servo motors.



Do you have any recommendations on where I should get a new heater core from?



-Deon

 

[MAleshire]

John--before you do anything else, make sure that the control knob for the temperature didn't just puke out. They break fairly regularly, and cost about $10 from the dealer.



Skip

 

[johncameron]

I'm guessing this is what your talking about?

 

[MAleshire]

John----No, I talking about the knob that fits on the black post in your picture. Look at the inside of the knob to see if it's broken. The knob is a cheap piece of junk and breaks fairly often. The same part fits on the mode selector. It's good to throw a spare in the jockey box. Looks like you pretty much have everything apart already. Let me know how it goes. Good luck!!



Skip

 

[johncameron]

John----No, I talking about the knob that fits on the black post in your picture. Look at the inside of the knob to see if it's broken. The knob is a cheap piece of junk and breaks fairly often. The same part fits on the mode selector. It's good to throw a spare in the jockey box. Looks like you pretty much have everything apart already. Let me know how it goes. Good luck!!Skip

I just looked at that and my selector knob turns the shaft... . It works#@$%!



Do you have any other ideas? I was hoping it would cost only 12$ :-laf



Thanks John

 

[DLausche]

The air temp is controlled by a electric servo motor that actuates a door inside the heater. The air blend door lets air bypass the heater core in cold and forces the air thru the heater core in the hot position. The blend door is the only one that is electrically operated and is the door that is immediately next to the heater core itself. From the drawings in my service manual I am not able to discern if the servo motor is on the top or on the bottom of the heater unit. The removal/replacement instructions for the blend door motor do state to "... remove heater assembly from vehicle... " so from that a person could guess that it is on the top of the heater unit. It should be within a few inches of the heater core in the center of the AC/heater assembly. Maybe the electrical connector at the motor just did not get hooked up when the heater core was replaced?

-Deon

 

[DLausche]

Blend Door Motor

I just checked my truck. The blend door motor is *easily* visible from the passenger side. The pic here is taken from the passenger floor area looking up and towards the center trans hump in the middle. Hopefully the electrical wire is simply not plugged in on yours as this would be super simple to remedy. I am not sure why my repair manual states to remove the heater assembly as it looks like this motor would be fairly easy to swap out from the bottom without removing anything.



-Deon

 

[johncameron]

I think I found my problem... ... ... usually electric motors don't like a bath in coolant.....



John

 

[Joe Mc]

Yea, I keep telling the people I work with you can't have a plumber install an electrical service and you can't have an electrician install plumbing services. But, they just don't get the idea - electricity and water don't mix . . .

 

[johncameron]

Yea, I keep telling the people I work with you can't have a plumber install an electrical service and you can't have an electrician install plumbing services. But, they just don't get the idea - electricity and water don't mix . . .

I guess I shouldn't admit this... ..... I changed my heater core with a buddy:-laf

 

[Joe Mc]

I guess I shouldn't admit this... ..... I changed my heater core with a buddy:-laf

OK - Who's the Plumber and who's the electrician? I knew it!

 

[johncameron]

My new servo motor assembily will be in tomorrow, hopefully it is the problem... ... the stealership wants 150+ fer it#@$%!#@$%!#@$%!#@$%!



John

 

[johncameron]

A quick update, the new servo motor assembily works great! 190$ later#@$%!#@$%!#@$%!#@$%!



Thanks everyone, John

 

[johncameron]

OK - Who's the Plumber and who's the electrician? I knew it!

I'd say were a bit of both:-laf

 

[DLausche]

Good to hear you got it working again. I'll assume you did not have to remove the entire heater assembly to change out that motor like my factory repair manual says to do.



-Deon