A/C disable when defrosting [Merged 9-6]

[dave99gst]

i will just leave it like it is i guess i just thought maybe something was screwed up cause my talons never did this but if its normal i will leave it alone.

if it isnt broke dont fix it

if your talon(s) never did it -- they were broke.

 

[Mist3r Spool]

Or, if you think it'd help (it won't), just unplug the microswitch on the heater control which contacts when you turn to defrost.

When I pulled the fuses out of the box, it didn't do anything for some reason, probably because I'm having a crapload of electrical issues right now.

 

[lesb1978]

First off I know this probably isn't the best place for this thread but i don't think it really fits in any, but mods if you have to close it or move it I understand.


Now, I've already searched and came up empty. I 'm wondering if there's a way to override the ac compressor when you turn on the defroster. I've done this in several other vehices, mostly all domestics but in several different makes and models. Usually it consists of breaking or bending a tab in the HVAC. Is this possible?

 

[VelocitàPaola]

Um... forgive me for my ignorance, my car stays in South Florida, where I never need the defroster at all; but, why exactly do you want to do this?

You can turn the blower on while the A/C compressor is off...

 

[lesb1978]

in almost every car made now when you switch to defrost the ac compressor kicks in why i have no clue but it does rob power

 

[bullettdsm]

Yeah, the AC kicks on when you hit defrost. It helps to defog the window quicker. That's the "conditioner" part of the AC.

MB

 

[Defiant]

There's a microswitch on the defroster control. Pull the panel and there it is. Disconnect the molex plug, and you're done.
AC is used during defrost because cold air won't suspend as many water molecules as warm air will. The defroster air is run past the chiller to drop the water out, increasing the efficiency of the defrosting process by about 70%.
Keep in mind that efficiency percentages are completely made-up about 85% of the time.

 

[denniegst]

i have a 97 gst and whenever i turn on the heater and the dial is on the defrost, my ac would turn on automatically even if the ac button isnt turned on. I use to own a 98 gst and this didnt happened. I was wondering if its just the 97s or is it just mine?

 

[Killa_dsm]

i have a 97 gst and whenever i turn on the heater and the dial is on the defrost, my ac would turn on automatically even if the ac button isnt turned on. I use to own a 98 gst and this didnt happened. I was wondering if its just the 97s or is it just mine?

Mine does that as well. But I think the AC only comes out of the vents by the window to defrost it.

 

[Piranha451]

What you describe is normal. In fact, the majority of the cars out there all do that when the defroster is turned on.

 

[denniegst]

ok just curious, my 98 never did thats all. Thanks for the clarification.

 

[caseymish]

Ok so heres the deal. All my heating componets work great when put on the settings that don't defrost. The air blows nice and hot. But even with the thermostat set all the way n the red as soon as I switch over to either of the defrost settings the green light on my little A/C button turns on. Even with the A/C button not pushed in it still comes on. The air blows but not hot like the other settings, now it just blows warm. The A/C by t self works great blows ice cold.

I am guessing it has something to do with the electricals but other than that I have no idea. What do i do?

 

[Killa_dsm]

Nope this is normal. It usually blows the cold air on the windows to defrost them, or keep them from getting foggy.

 

[snowborder714]

Killa is right. Also, the A/C helps to dehumidify the air. This dehumidified air is less likely fog the windshield up as well as it won't put condensation on any of the windows.

Another reason this is that the A/C should be run every so often so that it keeps charged and how often are you really going to turn it on in the winter?

 

[caseymish]

Ok thanks. I just figured somethig was wrong because my buddies GS didn't do it at all. Ok good to know thou.

 

[Eclipse98_RS]

All cars are like that. Just turn the nob towards heat and hot air will come out.

Do people seriously not know this? Cmon people this is embarrasing.

 

[ZenkaiRacerDsM]

Uh yeah. What were talking about is not having the a/c compressor come on just because the hvac is in the defrost position.

Thats usually where I like mine to be, but I dont want my compressor running the whole time.

 

[wret]

Relax. The compressor is designed for continuous duty. You don't unplug your refrigerator because you're worried about the compressor do you? Activating the air conditioning to dry the air is the fastest way to clear the windshield. This has been known for many years before automotive engineers started wiring them together. This simplifies the operation and provides faster windshield clearing for those that never would have figured it out.

If you want to maintain a warm/clear windshield without the continuous usage of the AC compressor, rotate the climate control knob away from the windshield icon until the compressor goes off. You'll still get some warm air directed toward the windshield.

 

[Defiant]

Thats usually where I like mine to be, but I dont want my compressor running the whole time.

If that's more an issue than having a fogged windshield, pull the radio and reach up in there to unplug the microswitch that turns on the AC circuit. It's on the defroster linkage.