Yous Guys With Heat Only Trucks

[92 s10 project]

Starting to go through all the stuff behind the dash on my S10 in preparation for re-installation and I'm trying to figure out exactly whats needed to run just the heat.

My truck came with an abomination of an aftermarket A/C system installed on it. These jokers really screwed some stuff up with all the vacuum lines and the wire harness from the heater and radio stuff on over to the passenger side. Tons of splices everywhere, cut vac lines, ect.

I have a blower box from a non a/c truck, the HVAC switch panel, and the wiring from the switches on out to the blower motor and box resistor. That was easy. Only thing I don't know about is what vacuum lines and valves are required to make my heat, defrost, and vent functions work properly.

If anyone has any helpful info they can shoot my way it would be much appreciated.

[tolowinorlando]

i am heat only but have never removed my dash (yet) but i am wondering the same thing as u are

i want to find out what i need and what i dont need

[87wildside]

My '87 didn't have any vacuum under the dash but the '91 I swapped the motor from did. Sorry I'm not any help.

[MadMikeZ28]

Hard to say what you need since your is an aftermarket system. But the heat only systems just use the defrost vents and floor. Your aftermarket one should have done that as well. Heat only also did not have the door under the cowl that blocks off the fresh air for max a/c and if I remember right heat only did not use the vacuum motor for the inside vent by the passengers feet.

[irondukecharlie]

I had A/C. Pulled the compressor, condensor and blower. Went to the junk yard and pulled a heat only blower housing and cut its wiring harness and spliced it in along the engine side of the fire wall. Should be a yellow blue and orange. Seems to work fine.

[92 s10 project]

Ok I should have explained my situation a little more clearly. But Im pretty sure I have it all buttoned up now.

Main reason I posted was because I couldnt find my dealer manual and was afraid it was thrown out, but alas it was recovered so that helped me tremendously, I cant help but say it was the best $35 bucks I ever spent on this truck.

Anyways, my truck was a heat only truck to begin with, and the aftermarket system that was installed went in place of the factory blower box, and still used the factory heat only blower motor. It even mounted the compressor in a non stock location, so they kept the factory idler pulley and bracket in place, mounted the compressor elsewhere, and used a rediculously long belt.

Inside the truck they actually used a factory A/C control panel, but they chopped up all the vacuum lines to put tees in them and route them to a few other vacuum operated doors and valves and junk in odd places....I couldnt even figure out what most of it did but I threw it all away, lol.

According to my book the heater only system uses two vacuum operated valves to open different doors to decide where the air was to go.

I have got everything behind the dash straightened out, I just have to double check where exactly I get the vacuum source and what else needs to be hooked up to the vent door in the cowl and the passenger floor vent.

Sorry for the book, I will be taking care of the rest of these details tomorrow when Ive got light and can go read all of my labels on the rest of the parts.

Once I get it figured out Ill try to answer all questions if anyone has them.

Next is tackling the destroyed wire harness behind the dash...

[ddg1025]

just wondering since you are getting rid of your a/c system and you said it was aftermarket if it is anything like mine. you can see some pics of mine on the post "does anyone have dealer installed a/c?". if you could show me some pics of your a/c components i may be interested in buying them.

[92 s10 project]

ddg1025, I checked out your post. My blower box and dryer looked pretty close to what yours does, if not identical. As far as the compressor goes, I cant tell you what it was like. I ditched the ac compressor about a year ago, then I took out the condenser when I replaced the radiator about 6 months ago, and I'm just now getting around to swapping over the box and all the rest of the junk added to the truck.

[ddg1025]

do you still have any of the ac lines there is 3 of them that i need and a local shop i went to wants to charge me like 50 bucks a piece for them. if you still have any of them i would like to see what they look like and maybe buy them from you.

[MadMikeZ28]

Check these guys out. They have a location in Sparks.
http://www.hfeweb.com/
You can get the hose and fittings and put it together yourself or have them crimp fittings on for you.

[92 s10 project]

Sorry ddg, I ditched everything but the electrical side of it some time ago.