Heater stuck on max heat. :(

bmoeller

bmoeller

New member
Joined
Jun 10, 2007
Messages
329
Need a bit of help guys.

Got a '92 in Feb, and the heater is still stuck on. This is my first 1st gen, so I'm in new territory.

Don't know how the controls work for sure. Fan works, and the "off" button turns the fan off, but that seems to be it. Blend door moves freely, and no functioning A/C (yes it is charged, so good there).

There is a vac operated valve of some sort on the one heater hose. No vac on that line, and no change in temp with a hand operated vac pump is hooked up (and no leak down on the pump gauge). Either the valve is stuck open or,..........

Any ideas?

TIA.
 
I have a club cab with the rear sliding window. I already have them ALL open, unless it is raining, then it sucks BAD! :lolly:
 
The little vacuum-actuated valve on the heater line only comes on during "Max A/C" and doesn't seem to do much.

I'm willing to bet that the problem is in the blend door. Are you totally sure the door is still connected to the lever?
 
You can hear the blend door move when it goes from full open to full close. Wouldn't be impossible if that valve was plumbed wrong. Truck has a different body than stock

But, I solved the heater problem with 2 ball valves like my KW. :D

Now I just need to figure out how the vac is hooked up and controlled by the switches and such.
 
There are multiple doors; three mode doors are vacuum-actuated and control where the air sucks in and blows out from, the blend door that controls airflow over the heater core is cable operated.
 
That is what I was thinking, but wasn't sure. Figured the blend door was moved by the cable. It moves. Need to figure out if the vac is even hooked up to the controls or not.

32024_432216646677_658431677_5645753_4505570_n.jpg
 
You must log in or register to reply here.
Back
Top