Seems like the HHR SS is similar to some other vehicles I have owned (Toyota Tundra, Saturn L100), in that the manufacturer has "dumbed down" the user choices by not allowing the choice of air conditioning in any defrost modes. I.e. it's always on. I successfully disabled this in the Tundra through disconnecting some wires, thereby allowing full choice of when I want air on or not.

Does anyone know of any online step by step instructions as to how this can be done with the SS? Has anyone done this procedure? I'm quite sure the dealer with not perform it if requested. In these days of high fuel prices why have the air conditioner on when it may not be needed?

 

push the button?

 

RTM?

 

The reasoning behind the AC compressor being on in the defrost mode is to dehumidify or remove the moisture from the cabin air, thereby helps to keep the windshield from fogging up. Although in the northern climates where it gets colder, I don't know how much that would help. As far as fuel economy, I haven't really notice a difference w/AC on or off at highway speeds

 

Well . . . With GM as far as I can remember the AC kicks on when in defrost mode . . . .

I don't even understand why one would want to run defrost without AC . . . cause it don't work worth a damned without it . .. .

 

In humid weather it would be nice to be able to drive with the outside air blowing on the windshield. It would help prevent inside fogging (though not as much as with the AC) while not generating the outside condensation you get when the cooled inside air cools the windshield to a temperature lower than the outside air, thus constantly creating outside condensation.

I know I can feel a difference in power when driving uphill, from running the compressor at all. If in defrost mode, the compressor runs, even though the AC light is deceptively unlit. You'd think you should be able to blow air at the windshield without having to run the compressor, but I don't know of a way to do it in the SS. Probably they got tired of too many consumers complaining about how the defrost didn't work, because they didn't separately engage the AC like they were supposed to do when blowing air at the windshield.

Forcing the cooled air onto the windshield sucks in humid weather, though. If you have the temp turned down, it will generate condensation on the outside every few minutes. So the trick is to keep turning the temperature up high enough that it doesn't do it. On mine I have to turn the temp dial up at least 4 clicks from cold so as not to get this. It really is kind of a hassle. I would be OK with it as long as the AC indicator would light up when the compressor is running. As it is now I have gotten pretty anal about always checking to make sure the air is vented away from the windshield in my "preflight check". Though sometimes I still find I've been driving around with the stupid compressor running for half an hour. Not perfect, and definitely irritating, but a minor factor in an otherwise overall excellent and exhilarating driving experience.

 

 

Read The Manual?

 

RTM = Read The Manual (or Release To Manufacturing in the software industry).
RTFM is less polite...

ChevyMgr: I just wanna take a minute to say how much I appreciate your presence on this site. I can't count the number of times I've seen you contribute solutions, knowledge, and ideas. I am sure I speak for numerous others as well.

 

The main reason auto makers went to the compressor coming on in defrost mode was in the northern climates people were only using the air for about 3 months or less a year and the compressor would freeze up due to lack of use for 9 months causing a huge repair/warranty claim.
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