I have an efan on my 95 but have never hooked up the a/c override wire on it. I pulled up the wiring on the ac system in one of the books I have. But I’m not seeing a way to hook it up so the fan does not cycle every time the compressor cycles. I would also like to make it so the fan does not cycle while in defrost. Has anyone hooked one up?

 

There is a way but not for it not to come on in defrost

 

Looking over the wiring. It looks like I can tap into the wire coming off the dash switch. It goes from the dash control through the high and low limit switches then into the pcm. I would assume that would be a 12v input.

 

do you know where to tap into it? I guess I could just unhook the wire from the controller during the winter.

 

Anywhere between the control head, and the low pressure switch.

 

once I took another look at the correct wiring schematic that’s where I was thinking I could tap it. I guess I would just have to unhook it in the winter to keep it off when using the defrost.

 

Yeah, I tend to disable the compressor as well in the winter. So far as I am concerned, if I am trying to 'defrost' my windshield, all of the air the system draws in is already refrigerated, and thus, not carrying much moisture.

 

AC trigger on the HVAC controls I believe is 12 volts. Let me get back to you though to be sure. That's where i planned to tap in to add a AC helper fan

 

Refrigerated yes but if you breathe the moisture in that will cloud up the windshield. I want to put a switch on the compressor wire to disable it when I'm trying to heat up the windshield to melt the ice. Have to wait till the engine heats up enough to compensate for cold air the defroster is making. If I'm late getting out of the house i have to wait for it and it makes me late for work. Of course moving to a warmer climate is in the plan.

 

For the most part, I try to park in the garage during the cold weather. No frost on the windows that way. Regardless of how cold it is outside. If I goof..... and leave the truck out, I'll just start the engine, and let it idle while I scrape the windows, then I drive away. Going east some mornings is interesting..... but, I live out in the sticks, so, I don't really see ANY traffic for the first five minutes of the drive, and by then, the engine is warm, and clearing my windows..... If you live in town, probably not a viable option.