I have been told that my defrost will not work properly if my AC isn't functional. I have a serious leak somewhere that caused all my refrigerant to leak out within 4 days of a recharge. I will not be fixing the AC but will be converting the compressor over to on board air in the future.

I was told the defrost cycles the ac compressor for some reason when it is in use. Is this true? Since my system has 0 refrigerant i don't want to harm the compressor. Also will not having A/C effect my defrost or heating ability?

 

Yes that is correct, the a/c compressor does come on when using defrost to take the humidity out of the air. If your refrigerant is low it will not cut on due to there being low pressure

 

How about a bad compressor clutch? That's what is wrong with mine

 

Well I have the same issue, no ac. It has a huge leak somewhere and my defrost works fine

 

On a rainy or snowy day it will suck without it. It will eventually defrost but it will take much longer and probably won't do the whole windshield properly. An old trick was to clean the inside of the windows using newspaper instead of paper towels to prevent them from fogging. And they apparently also come out cleaner.

 

Deleted my entire AC system and defrost works fine. Than again I haven't seen winter yet...

 

are you sure that the leak isn't being caused by the a/c pump itself?

take off your serpentine belt, turn the a/c on with the key in the "run" position. the a/c clutch should engage, and you should be able to turn the pump over by hand. if you can't do that, I'd suspect that the pump itself is the culprit of the leaking coolant.


that said, if you're worried about wrecking the pump, just disconnect the wires going to the pump. it won't throw a check engine light, and will keep you from burning up the pump. and your defrost will work just fine.

 

I would think without the a/c compressor engaging the defog (warm/humid ambient) would not work. The defrost (cold/dry ambient) should work fine.

 

The defrost uses the a/c whenever it is on. So no it should not work very well.

 

My A/C doesnt work and my defrost works fine... winter and all.

 

X2

 

Thanks for help guys. Im not trying to track down the leak. AC compressor is fine by the way. Whatever it is thats under the dash is where my leak is because i could smell the refrigerant in the cab. IVe turned my defrost on and it nice and warm just wanted to make sure the compressor wouldnt try and kick on. I ran defrost for about 4 mins and it never engaged so i guess im in the clear.

 

Quite true.

The defroster can work without the aid of the AC's dehumidification, but it does it by applying warm or hot air.

 

With running hot defrost air and ice/snow on the windshield, you run the risk of cracking the glass. Ask me how I know.

 

The defroster works by applying hot air to the inside of the windshield whether the A/C compressor runs or not. The reason the defroster works better with the A/C working is because the air is dehumidified and will better absorb the condensation on the inside of the glass.