AC defrost disable - Page 4 - Fuel Economy, Hypermiling, EcoModding News and Forum

Diesel_Dave · 03-20-2012, 01:33 PM

Eventually I want to put in a relay in the AC compressor supply wire that's triggered by by me pushing the AC switch (snowflake button).

slowmover · 03-21-2012, 10:56 AM

Well, we had a warmer than normal winter, with continual records being set in the central and upper Midwest. But the relay sounds good!

Diesel_Dave · 03-21-2012, 02:54 PM

Quote:

Originally Posted by slowmover

Well, we had a warmer than normal winter, with continual records being set in the central and upper Midwest. But the relay sounds good!

No kidding, It's close to 85 degrees today! I need to mow my yard and it's only March!

Not that I'm complaining--my mileage has been rising rapidly with the temperatures. I've been breaking my own records left and right the last few days (averaging 42.8 mpg on the overhead over the last 7 days!)

pjbgravely · 03-23-2012, 11:53 AM

Thanks for the inspiration. I just finished mine. I went into the heater controls add add a switch to disable the AC. If I disabled at the compressor the cooling fan would still run on my car.

Diesel_Dave · 03-23-2012, 09:52 PM

Did you use a relay, or switch it directly?

pjbgravely · 03-23-2012, 11:14 PM

I used a switch. I found the two wires that go to the heater control that turns the AC on in certain settings. I cut one of the wires, added another switch so both have to be closed to allow the AC to work. I could have also just used my switch so I could turn on the AC in any heater position like some cars are set up.

t vago · 03-23-2012, 11:25 PM

Quote:

Originally Posted by pjbgravely

I could have also just used my switch so I could turn on the AC in any heater position like some cars are set up.

This was the route I took.

Basically, I modified my climate control panel to add a cheapie Radio Shack microtoggle switch, then soldered two wires to the switch. One wire went to the panel's power supply, and the other wire went to the wiring connector pin that sent switched power to the engine computer to engage the fan and A/C compressor. Works like a champ.

I did this because my stock climate control panel only disabled A/C in the panel vent position. In all other positions (panel and floor vent, floor vent, defrost, A/C panel vent, and MAX A/C), the stupid thing engaged A/C.