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  #1  
Old 01-14-2010, 04:55 PM
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Climate Control Issues

I switched over to heat a few days ago, now when i try to switch back to a/c it won't do it. I've tested the ac compressor and no voltage is going to it. fueses are good, compressor and clutch are good. I'm assuming there is no way to test the climate control panel, is that most likely the culprit?

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Old 01-14-2010, 05:44 PM
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Wanted to add that the fan will turn on and off, that's about it, it doesn't switch vents. If I run the heat all the way up it gets hot. If i run it to cold it turns the heat off but that's about it, no a/c.
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Old 01-14-2010, 08:18 PM
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Might be too cold out for the A/C to come on. It will not come on if the temp is already at or below what it is set for. Don
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Old 01-14-2010, 08:26 PM
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I had a CCU that was doing that. After going to full heat it would not "recover" and cool off in any position.

I had to figure out a "routine" of pushing the right buttons to get the heat to switch off. Pushing the defrost button and then pushing the economy button with a couple other buttons at the same time. Eventually it would start to cool off.

I lived with it for a while. Replacing the CCU cured it.

Be sure to check the fuse for the compressor in the fuse panel. That fuse controls a couple things. You need to do some testing before you condemn the CCU.
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  #5  
Old 01-14-2010, 08:36 PM
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If there is no voltage in the compressor, you could be low on refrigerant.
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Old 01-14-2010, 08:37 PM
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yea checked the fuse, even replaced it to be sure.

I thought if the temp button was all the way to the cold it would come on no matter what? Anyhow it was 77 out today I'm pretty sure the a/c should work!!!

I figured it was the climate control unit just wanted to be sure before i bought a rebuilt one, they ain't cheap!!! What other tests do I need to do from here?

Thanks for the help!!
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Old 01-14-2010, 08:38 PM
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Quote:
Originally Posted by my123ca View Post
If there is no voltage in the compressor, you could be low on refrigerant.
There is no voltage TOO the compressor clutch, that should be on regardless of coolant level should it not? If I unplug the cable to the clutch with the a/c on i should have 12 volts shouldn't I? I guess I could check coolant pressure, all the lines on the a/c are only 3 years old, that would suck if there was a leak already.
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Old 01-14-2010, 08:41 PM
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Did the A/C work fine and now all of the sudden it won't?

As mentioned above, don't condemn the CCU until you have checked the rest of the system. Charge in the system, wiring over around the drier (low pressure switch), Kilma relay, wiring at the compressor, the list goes on....
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Old 01-14-2010, 08:45 PM
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Everything worked fine on the a/c two weeks ago, I never use the heat, it's been a year since I used it. Turned the heat on two weeks ago and heat worked fine, then today went to turn the a/c on and NOTHING. Also when i click the vents, like defrost, floor, econ nothing changes. I can turn it off, or on that's about it. If I crank the heat up the heat kicks on, if i turn it to a/c the heat turns off, or at least it's not as hot, but no a/c
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  #10  
Old 01-14-2010, 09:02 PM
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Quote:
Originally Posted by phinsup View Post
There is no voltage TOO the compressor clutch, that should be on regardless of coolant level should it not? If I unplug the cable to the clutch with the a/c on i should have 12 volts shouldn't I? I guess I could check coolant pressure, all the lines on the a/c are only 3 years old, that would suck if there was a leak already.
You will not have voltage TOO the compressor if you are low on refrigerant. One way to check is to bypass the pressure switch and see if you have voltage to the clutch cable.
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Old 01-14-2010, 09:03 PM
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Quote:
Originally Posted by my123ca View Post
You will not have voltage TOO the compressor if you are low on refrigerant. One way to check is to bypass the pressure switch and see if you have voltage to the clutch cable.
Ahh I did not know that, I will check that tomorrow.

thanks!
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  #12  
Old 01-14-2010, 10:42 PM
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Well that answers that, not a drop of coolant in the thing. must have a pretty good leak somewhere
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1984 300D Turbo 169k

"Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover."
-----Mark Twain
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  #13  
Old 01-15-2010, 04:28 AM
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Check the evaporator temperature cut out switch. That can prevent the AC clutch from getting power. The switch should be closed at room temps and then it opens when the evaporator nears freezing, but they can fail open.


**Edit: whoops, missed that last post.

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