Pull the plug on that compressor

[ksa8907]

The op has it right, just pull the connector for the transducer. It will make the system think there's no pressure and thus oil in the system so it wont turn on.

[Ryland]

Our work truck does the same thing only you can manually turn it off by hitting the button.
As I understand it, vehicles that have the A/C come on more often last longer because the oil is getting circulated and the seals aren't drying out.

[wungun]

I know on the Fords, if the temp is below a certain temp (4 degrees C. iirc) the compressor won't kick on with defrost...
In my Fiesta, I monitor the outside temp on the dash and stay away from defrost/feet-defrost if the temp is too warm.
With that said, I'd love to rig up a switch to the compressor.
On my Focus SVT, it was simply a matter of unplugging the two prong electrical connection behind the HVAC knob.
This way if I need the air dried out, I can simply switch on the AC myself.

[serialk11r]

New car problems. I guess this is one of the few features of (sorta) old cars that's good for fuel economy, no automatic anything besides fuel injection and all However I think it's probably offset by my "dumb" alternator which runs at 14.6V at anything above idle at all times... :/ Probably should look into doing something about that when the battery decides to quit due to being abusively charged all the time like that.

[wdb]

Originally Posted by ConnClark

Actually its a safety feature to keep the windows from fogging up. At times I wish my AC actually worked.

What he said. The feds have standards for the windshield defrosting capabilities in passenger vehicles, and turning the AC on when defrost is selected is an easy way for manufacturers to meet the standard. Cars I'm familiar with have been wired this way since the 70's.

Originally Posted by Frank Lee

My '84 Tempos had nice illuminated a/c compressor switches; too bad that feature went away.

Went where? I have that in my 2008, 2005, and 1994 cars, and my wife has it in her 2011 car. In my 2005 car, when I select defrost and the AC comes on, I just turn it back off again by pushing the button. My 2008 car was a bit more nefarious and I had to disconnect a wire to defeat the AC when defrost is on. I can still just push the AC button and turn it on though, and I often do because that car is not exactly great at defrosting or defogging.

[user removed]

The defroster works great without any AC. Maybe I just keep the WINDOWS cleaner than the average new car owner, including my wife. I think when I get ready to hook it back up, I'll just put a toggle switch in the ground circuit and hide it under the dash. That way I can run it occasionally in the winter to keep the seals from drying out. I guess I like some humidity more than none, which dries out my sinuses, then they will swell up. Happens in the fall when we first turn on the heat, even with a heat pump.

regards
Mech

[ron]

my techoma does the same thing on defrost, Im not sure if the compressor engages when defrost/floor heat is selected I will go outside pop the hood and check

[ron]

OK here is the answer to my own Q. , the compressor comes on in both positions defrost and floor/defrost both turn off when you manually turn off the fan. that switch Old Mechanic is talking about seems like the fix I like. one more thing on the todolist.

[BackroadBomber]

My 2011 taco kicks on only with the defroster. I pull the fuse every winter because with my little 4 banger I can feel the power loss every time it kicks on and it's extremely annoying. Plus I see my mpg drop by about 2 on the scangauge every time it happens. I'm sure you're fine, OP, pulling the plug in va, but here in buffalo if I did that the plug would get corroded from the salt and calcium they use on the roads all winter long.

[Frank Lee]

Went where? I have that in my 2008, 2005, and 1994 cars...

My '84s have it but my '92s don't. Also my '94 F150 doesn't.