A/C issues - compressor not turning
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From: Ft. Worth, TX
A/C issues - compressor not turning
The A/C quit working on my 2006 the other day... driving down the highway for ~15mi, the air was working fine, and then I noticed it was blowing hot. A few minutes later, it went back to cold, and then a few more minutes, back to hot. It did this three times in the 15 miles. When I drove the truck the next day, the A/C was not working at all. I figured that it may be low on freon because the compressor is not kicking on, so I bought a self charging kit and tried it out. When I hook it up, the needle on the gauge is completely pegged out to max, and I can't get the system to take any of freon.
I don't think the gauge works right unless the compressor is turning (is this right?), so I'm not worried about the reading (yet anyway). I tried the can on my wife's 4Runner (A/C works), and it seems to work fine. The gauge reads well and the can transfers freon (it gets cold in my hand). Any idea why I can't put any in the truck? What else should I look at?
I don't think the gauge works right unless the compressor is turning (is this right?), so I'm not worried about the reading (yet anyway). I tried the can on my wife's 4Runner (A/C works), and it seems to work fine. The gauge reads well and the can transfers freon (it gets cold in my hand). Any idea why I can't put any in the truck? What else should I look at?
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Shure you have the vave fully seated it has todepress the valve in the fitting for gas to be able to enter the system. Even with gauges I sometimes have to clean or play with the snap connector to fit all the way.
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The compressor needs to be turning to check the freon levels.
It could be as simple as the air gap on the compressor clutch (verified by backprobing the connector for voltage with a/c switched on)
Or the air drier could have broken apart and sent silicate throughout the system, which eventually locks up the compressor.
With the system off and engine not running you'll likely see 50-85 psi depending on the ambient temp, but isn't a good verification of freon levels until the system is running while using both a low pressure and high pressure gauge.
Josh
It could be as simple as the air gap on the compressor clutch (verified by backprobing the connector for voltage with a/c switched on)
Or the air drier could have broken apart and sent silicate throughout the system, which eventually locks up the compressor.
With the system off and engine not running you'll likely see 50-85 psi depending on the ambient temp, but isn't a good verification of freon levels until the system is running while using both a low pressure and high pressure gauge.
Josh
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I would start by checking the air gap of the clutch and back probing the compressor, low pressure and high pressure switches for voltage with engine running and A/C switched on.
Josh
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From: Ft. Worth, TX
Correct, but as of now it sounds like you should have enough R134 in the system to at least trigger the system.
I would start by checking the air gap of the clutch and back probing the compressor, low pressure and high pressure switches for voltage with engine running and A/C switched on.
Josh
I would start by checking the air gap of the clutch and back probing the compressor, low pressure and high pressure switches for voltage with engine running and A/C switched on.
Josh
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How exactly do I go about checking the air gap? I'll check the switches to make sure that they are operating. I'm guessing that with the A/C on and the truck on (does the engine have to be running, or can I just have the key on?) there should be 12V at all of the pressure switches and compressor?
For air gap:
http://ww2.justanswer.com/uploads/s4...l_and_6.8L.pdf
Also make sure the heater control valve vacuum line is connected. Grey hose above passenger valve cover inline with the heater hose.
Josh
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Elder User
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From: Ft. Worth, TX
No dice on this one. Gotta find my 12V tester to check if there is power there or not. Where is the high pressure sensor?
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From: Ft. Worth, TX
Update on this - I finally got around to messing with this on Sunday and the issue turned out to be the relay that is under the hood. I switched out out with one for the trailer lights, and the compressor kicked right on! I swapped it around a few more times to make sure it wasn't a fluke, and it doesn't appear to be. I got lucky on this one (even though I spent $50 on freon); now I just need a new relay for my trailer lights and I'll be good to go.
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From: Middle Tn.
Update on this - I finally got around to messing with this on Sunday and the issue turned out to be the relay that is under the hood. I switched out out with one for the trailer lights, and the compressor kicked right on! I swapped it around a few more times to make sure it wasn't a fluke, and it doesn't appear to be. I got lucky on this one (even though I spent $50 on freon); now I just need a new relay for my trailer lights and I'll be good to go.
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From: Ft. Worth, TX
I have a set of gauges that didn't do me any good because the compressor wasn't turning! 
The mistake I made was opening the can before I knew for sure it was needed. It's not a total loss as I'm sure that I'll use it at some point in one of my vehicles.
The mistake I made was opening the can before I knew for sure it was needed. It's not a total loss as I'm sure that I'll use it at some point in one of my vehicles.