heater core bypass question

[SuRrEaLNJ]

first off i will admidt i havent really looked at this thing myself, but i know the 94 LTD i picked up has one, and munk (my 91) does not

now in my infinite wisdom, i deleted munk's a/c and removed the carpet and all cabin insulation. it can get kinda warm in there now when id like it to not be

anybody know what it would take to make the factory valve from the 94 work in the 91 offhand?

i figure this way id have a better chance of blowin cooler air from the hvac if i can keep the in box temperature down

 

[BrooklynBay]

I remember seeing a thread from Shamaal many years ago where he did this to his Navajo. He doesn't have that vehicle anymore.

 

[SuRrEaLNJ]

wow, did that narrow my search down

http://www.explorerforum.com/forums/showthread.php?t=190431

 

[SuRrEaLNJ]

gonna have to look at the system as id like to be able to close the valve with the recirc door open to get outside air in, but this is definitely the right idea.

actually in hindsight stealing vacuum from something is a no brainier, this mans a genius. it so didnt seem that simple 5 minutes ago

 

[Maniak]

The heater control bypass valve uses vacuum to keep the water out of the heater core. Soo, get a 12v solenoid that you can use to allow engine vacuum to pull on the bypass valve when you don't want water in there.

I was going to say pull it from your a/c control (max a/c sends vacuum down the line) but since you pulled a/c I guess you don't have the controls either...

The 1993 and 1994 heater and a/c controls send the vacuum down the line on both max a/c and in the off position.

edit: I just looked at the thread link you posted. That is mod we did to our '92. really helps the a/c in the summer.

~Mark

 

[SuRrEaLNJ]

i still have the controls, but i dotn know what works. the compressor, condenser, and the lines are gone, the rest is there

 

[Maniak]

Ahh.. then in your case, just set the control to "Max A/C" and tap into the vacuum line listed in the thread linked above.. that will keep hot water out of the heater core.

~Mark

 

[rsoby]

Can you think of any reason this mod could not be installed in such a way as to use a vacuum control valve inside the vehicle so that you could turn the heater core on and off at will. I have a 94 Ex and when you slide the temp control to cool and it allegedly shuts the door bypassing the heater core the heat is still pretty strong coming out. It would be nice to be able to shut it down and get cool air through the vents on days that AC isnt neccessary.

 

[SuRrEaLNJ]

you'd have to put in another vacuum switch that you could operate the valve from independent of what goes to the recirc door

the reason everyone, my self included runs it off that valve is all your adding is a "T" at the recirc door and a line to the valve, and using the existing supply and controll thats already there