71 c10 heater flap
 

So I have a 71 c10 w/o ac and the heater gets warm but not hot. when i adjust the heat control lever it doesn't change the temp of the air. i have already flushed the heater core and put a new thermostat in and it hasn't changed. so i am thinking it is the control flap. does anyone have a pic on how the flap works and how to access it.

Re: 71 c10 heater flap
 

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It is probably full of mouse nest. That will keep the diverter door from moving and it will also restrict the air flow.....

A common problem in these trucks.

LockDoc

Re: 71 c10 heater flap
 

thats what i am thinking, just not sure if there is an easy way to access it or do i have to pull it all the way apart.

Re: 71 c10 heater flap
 

You will probably have to completely disassemble it at some point in time but if you pull the blower motor and clean and vacuum that side out, then remove the plastic plug on the right side of the inside heater box (where the cable goes through) you can fish a lot of junk out with a piece of wire with a hook bent on the end of it. I have cleaned a couple of them out that way.... Worth a try anyway.

LockDoc

Re: 71 c10 heater flap
 

Got it fixed. The cable to the flap came unhooked inside the box. Now it is very hot. Crazy that something sp simple caused me to freeze in the winter.

Re: 71 c10 heater flap
 

:lol:.... Glad you found the problem and it was easy.

LockDoc