Found I have no vacuum line going to my heater bypass valve and it is zip tied closed. I found a broken vacuum line but it produces no vacuum no matter what I have tried. Does anyone have a schematic they can post of the vacuum control for this valve?

 

Well after some more searching I found that vacuum is only supplied to the heater core bypass valve in the Offposition or the Max A/Cposition. Turned out that I had found the correct vacuum line but it was clogged up from being exposed between the bottom of the evaporator box/blower motor housing and wheel well. I did not have much to work with and it was very tight but I managed to snip off a 1/2" and attach a vacuum line I had on hand that did the trick. I now have a working valve and working heater system. I had already flushed the heater core thinking that was my problem. Heater is now functioning as designed and blowing some hot air.

 

OK, good find, fix, feedback & to hear all seems well & your now Warm, while on the road again!!!!

 

The thing is cooking me out, I have to shut it off. I think the blend door is unresponsive or missing but that is way down the fix it list. In a couple of months it will be all A/C all the time anyway.