I've had this problem for a while. My HVAC controls are acting in reverse order. Like when i go to def. the car acts like it's in the off position, and when I go to heat or vent it acts like its in the AC spots. The air comes out in the right vents, but the compressor kicks on in the heat and vent positions and not in the def. or AC positions. I thought maybe the wire was hooked on backwards in the back of the control box, but I looked and I didn't see any way that it could be hooked up wrong. This isn't a really major problem, but its still really annoying to drive around with my compressor on when I don't need to. What do you guys think could be the problem. And on a relelated note, my fan doesn't work in the defrost position either, but it works in the vent and heat positions. I don't know if these problems are related, cause the fan problem just started recently.

Any help you guys could give me would be greatly appreciated.
Thanks

 

There are very small vacuum lines running underneath the dash that are all rigged up to the HVAC controls. I would assume someone took the dash off at some point in time and put the lines back incorrectly, which would swap the HVAC controls all around.

 

On the TGO main page, go to Tech Articles and to the Electrical section. You will find a link to 1986 wiring diagrams. Follow the link to the page that pops up and scroll down to the Air Conditioning section, and click on Vacuum Control. That is what you are looking for. As for the compressor operating when the heat is on, you have a wiring problem that should not be there. And as for the fan, are you talking about the main engine fan? That definitely sounds like a wiring problem.

 

I don't know if it is a vaccum problem. Cause the air comes out the right vents. Like when I have it switched to def. it comes out by the windshield, and when I switch it too vent, it comes out the vents in front. So I think its a wiring problem causing the compressor to kick on in the opposite positions. But I'll check the vaccum lines anyways.

 

That section also contains all of the related wiring diagrams you need.

 

thanks for your help guys, I'll try with those wiring diagrams and see if I can see whats up. Also, its the blower fan that doesn't work on defrost, not the engine cooling fan, sorry for the mixup.