A/C comes on when heater turned to defrost


2.4_Z
11-09-2006, 11:23 PM
I just bought my '99 Cavalier Z24 and when I turn on the selector to defrost setting on the heater my a/c light comes on and I can hear the compressor. Is this normal?

BTW this is my first post and thanks for all the other info on this forum. I will be a regular for sure here!!!

Kris

muff34
11-10-2006, 02:29 AM
I just bought my '99 Cavalier Z24 and when I turn on the selector to defrost setting on the heater my a/c light comes on and I can hear the compressor. Is this normal?

BTW this is my first post and thanks for all the other info on this forum. I will be a regular for sure here!!!

Krisyup they`re suppossed to do that .keeps the a/c compresor lubed and operational

Phife
11-10-2006, 08:25 AM
actually it has nothing to do with lubing the AC..

It turns on because AC can remove moisture from the air thus helping with defrost.

But since the heat selector is on hot it heats the air back up after the moisture was removed and the air was cooled.

MT-2500
11-10-2006, 09:51 AM
I just bought my '99 Cavalier Z24 and when I turn on the selector to defrost setting on the heater my a/c light comes on and I can hear the compressor. Is this normal?

BTW this is my first post and thanks for all the other info on this forum. I will be a regular for sure here!!!

Kris


Welcome to AF on your first post.
No problem no sweat no worry. They all do that.:grinyes: :grinno: :lol:
It is the way they are made to take the condensation off of the windshield and door glass.
Good luck with it

2.4_Z
11-10-2006, 10:05 AM
Thanks Guys!! That takes a load off me. I thought that I might have to spend some big bucks to have that fixed. Ah, well on to other issues. Thanks

muff34
11-10-2006, 10:29 AM
opps guess I dropped the ball on this one. I thought a/C compresor could use some lubing/cycling to keep it from seizing up when not in use. Seeing as how a/c is not used in winter months ,I figured maybe automakers would design system so that it would cycle even when a/c is not required at the time to prevent such seizing problems. Guess cars with out a/c do not defrost as well

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