ac compressor not cycling on/off ice buildup
08-16-2015, 11:36 PM
#16
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My understanding, from what I have been reading, is the compressor will not shut off. Try unplugging the wires at the compressor. If this does not shut it off then, you need to replace the compressor.
08-17-2015, 12:52 AM
#17
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Thank you Steve I will try that. You're correct, when the button is OFF in truck it stays on. It doesn't ever turn off. So I'm running truck with the fuse for ac clutch pulled. I have so little down time to investigate this. The part and labor is under warranty, unfortunately 500 miles from where I live... but that does happen when you're hauling all over. I need to rule out as many possible causes as I possibly can before I spend more money. Thank you.. will reply with result.
08-17-2015, 01:23 AM
#18
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Common fix is to top off the refrigerant as it is low. If this occurs again in a short period of time, you will have to find the leak.
08-17-2015, 05:07 AM
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I have a similar problem on my 03 after about 1/2 hour of driving the air freezes up and if I turn the ac off it will thaw out and work again but my compressor clutch does disingage if I turn the ac off. as I say the ac works fine untill it starts to freeze up then if I turn the ac off untill it thaws and then I push the button and it works again for a while. The drain tube is not clogged as if you let it idle with the ac on the water runs out of the drain tube but the compressor does not cycle. Any Ideas ?
Jim O
Jim O
Check/fix for leak, recycle, evacuate, recharge with the right amount of refrigerant.
08-17-2015, 06:52 AM
#20
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check to see if clutch is disengaging, when u pull the wires off and it still turns try tapping clutch with a hammer "tapping" if it stops replace clutch, as u know the compressor is working. The clutch has welded itself togather;;
08-17-2015, 09:20 AM
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Jim O,
Have you checked your refrigerant charge? Evaps will ice up if charge is too low. You will notice a light "frost fog" coming out of the vents as the evap begins icing.
Gary
Have you checked your refrigerant charge? Evaps will ice up if charge is too low. You will notice a light "frost fog" coming out of the vents as the evap begins icing.
Gary
08-17-2015, 03:33 PM
#23
Come on guys, focus. OP said compressor keeps running with AC turned off. It doesn't run with the fuse pulled. Low refrigerant will not make it run constantly, that will make it not run at all if everything is working correctly.
There is obviously a short from battery voltage to the clutch coil wiring somewhere. A schematic and someone that knows how to trouble shoot is needed at this point. Any further comments on this subject is purely conjecture.....
There is obviously a short from battery voltage to the clutch coil wiring somewhere. A schematic and someone that knows how to trouble shoot is needed at this point. Any further comments on this subject is purely conjecture.....
08-17-2015, 07:03 PM
#24
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Jim O
08-17-2015, 07:56 PM
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Yes you have to recycle the refrigerant before you open up the system.
No shortcuts.
08-17-2015, 08:08 PM
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The evaporator temp sensor signal might be checked for integrity by using a scan tool.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
08-18-2015, 08:45 AM
#27
The evaporator temp sensor signal might be checked for integrity by using a scan tool.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
None of those things will cause the compressor to run non stop, it seems like everyone is ignoring the facts and findings of trouble shooting......of course the evap will freeze up if the compressor never stops pumping refrigerant.
Find out what is keeping the clutch engaged with no call for AC.
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08-18-2015, 10:38 AM
#28
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The evaporator temp sensor signal might be checked for integrity by using a scan tool.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
Other than low refrigerant, restricted orifice tube would also cause freezing evaporator.
Have to do more diagnosis to determine what to do.
Replacing the temp sensor would be the same as replacing the evaporator.
It would take 4-5 hours to remove the evaporator.
Not for the original OP.
08-18-2015, 10:40 AM
#29
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Forget about the evaporator temp sensor now.
Have to do more troubleshooting on "the clutch was engaged when A/C was OFF".
Without fixing this you are going nowhere.
http://www.rambodybuilder.com/2004/d...42/8W-42-7.pdf
05 has the same diagram as 04.
ECM controls the clutch by grounding the A/C CLUTCH RELAY CONTROL signal, after receiving the A/C Clutch request from the A/C Control head.
Possible issues:
The wiring from ECM to IPM clutch relay was shorted to ground.
ECM failed to control the relay.
A/C control head failed remove the request for A/C clutch.
Have to do more troubleshooting on "the clutch was engaged when A/C was OFF".
Without fixing this you are going nowhere.
http://www.rambodybuilder.com/2004/d...42/8W-42-7.pdf
05 has the same diagram as 04.
ECM controls the clutch by grounding the A/C CLUTCH RELAY CONTROL signal, after receiving the A/C Clutch request from the A/C Control head.
Possible issues:
The wiring from ECM to IPM clutch relay was shorted to ground.
ECM failed to control the relay.
A/C control head failed remove the request for A/C clutch.
08-18-2015, 12:05 PM
#30
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None of those things will cause the compressor to run non stop, it seems like everyone is ignoring the facts and findings of trouble shooting......of course the evap will freeze up if the compressor never stops pumping refrigerant.
Find out what is keeping the clutch engaged with no call for AC.
Find out what is keeping the clutch engaged with no call for AC.