Disabling compressor with defrost
#1
Legacy TMS Member
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Disabling compressor with defrost
I was just wondering if anyone has disabled the ac compressor from coming on when the dial is set to defrost/defog the windshield. This just bugs the heck out of me when Im driving and the ac compressor is clunking on and off. Not to mention dropping my MPG further than it already is since the car is so fun to drive. If I want the ac to come on I THINK there is a button or **** some where on the the dash for that.
#4
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Originally Posted by ETNOATS
The ac light never comes on, but I will try it. The compressor kicks on automaticly.
I haven't noticed much if anything change in my cars MPG since I've been running the AC on it the past couple days...my MPG has actually gone up since I've used it
#5
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Originally Posted by GT98
The reason the compressor kicks in with the defrost is that AC also drys out the air passing through it, thus clearing your windshield.
I even had to take a parts guy out to my last car and prove to him that the compressor does indeed kick in when the defroster is used, and regardless of where the Heat selector is positioned.
#6
Tasca Super Boss 429 Member
Originally Posted by OKCMustangGT
That is exactly why the compressor kicks on with the defrost. If I am not mistaken EVERY car does this.
I even had to take a parts guy out to my last car and prove to him that the compressor does indeed kick in when the defroster is used, and regardless of where the Heat selector is positioned.
I even had to take a parts guy out to my last car and prove to him that the compressor does indeed kick in when the defroster is used, and regardless of where the Heat selector is positioned.
In many cars, that temp. control switch is in the compressor. You can add a cut out switch (solenoid) to the compressor and it will do the same thing.
#7
Originally Posted by ETNOATS
I was just wondering if anyone has disabled the ac compressor from coming on when the dial is set to defrost/defog the windshield. This just bugs the heck out of me when Im driving and the ac compressor is clunking on and off. Not to mention dropping my MPG further than it already is since the car is so fun to drive. If I want the ac to come on I THINK there is a button or **** some where on the the dash for that.
Raise the temperture selection.
#8
Tasca Super Boss 429 Member
Originally Posted by Badsnke98
Raise the temperture selection.
On defrost, it's automatic.
#9
the ac is automatic, it is to chage the humidity of the air on the inside of the car. To be honest, i would just leave it alone. turn the defrost on, get the windows cleared off, and then just kick it back off. With the a/c on, it will help clear the windows much faster. The change in fuel mileage is minimal from just the defroster.
oh and another little tip that somehow some people just dont understand (some, i am not saying everyone here does this... just a thought if anyone is reading this and wondered why their windows wont clear sometimes)... a defroster will pretty much never work if you leave it on the recirculate, you need to pump fresh air to get the windows cleared out properly. i have noticed it especialy true when it is raining.
taking HVAC in college is such a curse and a power... i look at everything in terms of heat and humidity now.
oh and another little tip that somehow some people just dont understand (some, i am not saying everyone here does this... just a thought if anyone is reading this and wondered why their windows wont clear sometimes)... a defroster will pretty much never work if you leave it on the recirculate, you need to pump fresh air to get the windows cleared out properly. i have noticed it especialy true when it is raining.
taking HVAC in college is such a curse and a power... i look at everything in terms of heat and humidity now.
#10
I think it actually says in the owner's manual (I sometimes do rtfm) that the A/C is activated when the defogger is turned on.
I believe the real issue is the clunking compressor, which others have complained about before. I don't know that I've heard one quite as loud as this current one.
I believe the real issue is the clunking compressor, which others have complained about before. I don't know that I've heard one quite as loud as this current one.
#11
To Prevent Dry Rot
This is turned on by default for a couple of reasons. One is dry rot. The rubber fittings etc. This keeps the system from drying out and malfunctioning. Big problem in the early AC years. And secondly health reasons. To prevent mold and mildew buildup in the Cabin section of the AC unit. Dry air....no mildew.
Thanks
Cheers!
Irish
Thanks
Cheers!
Irish
#12
Legacy TMS Member
Thread Starter
Yes my biggest peev was the clunking compressor, did try running it with the selector to the floor and got enough air to keep the windshield about 90% clear. Didn't think about the air being dried by the compressor. Luckily I live in coastal So Cal, or Nor Mex if you prefer, so I don't have to run the ac to often. Windows down, listen to the song of the engine and exhaust. Thanks for all the input.
#14
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The AC compressor doesn't come on in very cold weather because the low pressure switch in the system is always open. The gas cools and that little ideal gas law says that the pressure drops with the temperature in a closed system. Eventually, it will get so low that they low pressure switch activates (it is there to protect the compressor. You have to have enough gas in the system to move the oil), shutting off the compressor until the temperature rises.
All in all, it is good for the AC system to be used during the winter months. If you compressor clutch is clunky, you might want to take it in. Mine is VERY quite (but I do have a coupe and my windows are almost always up).
All in all, it is good for the AC system to be used during the winter months. If you compressor clutch is clunky, you might want to take it in. Mine is VERY quite (but I do have a coupe and my windows are almost always up).
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