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sprinkles08, Chrysler/Dodge/Jeep master tech
Category: Dodge
Satisfied Customers: 21432
Experience:  ASE Master and Advanced Certified, Chrysler/Dodge/Jeep Master Certified, Trans and Hybrid Specialist
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2006 Dodge RAM 2500: 5.9 Cummins Deisel AC compressor does not engage

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2006 Dodge RAM 2500 w/ 5.9 Cummins Deisel

AC compressor does not engage. When the AC system is turned "off" the power to the AC clutch assembly is 11.5 volts. When the AC system is turned "on" the power to the AC clutch assembly is 14.25 volts. Freon pressure in the system is 125 psi with ac system "off" and vehicle cold.

Since it appears as though the clutch is getting power, I assumed the coil to the AC clutch is bad. Therefore I tested the AC clutch restivity. The resistivity to the AC clutch is 3.95 to 4.25 ohms in one direction and 0 ohms when testing the restivity in the other direction. Also, when testing for an electrical short from the coil to the clutch housing, no short appeared.

Is the AC clutch coil good or bad and how difficult would it be change the AC clutch coil on the AC compressor while the compressor remains in the truck?
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Make sure your clutch has ground also. if you do have power and ground at the coil it will need to be replaced. I have seen a bunch of the 2006 trucks with bad coils. The voltage you see on the wire when the system is off is diagnostic voltage. The compressor is controlled by the TIPM, the module in the fuse box under the hood. It applies this very low current diagnostic voltage to the circuit to check for opens and shorts. The fact that the voltage is there both with the a/c on and off means the TIPM and wiring are ok, all other external parts of the system are fine and the problem is contained to the coil. You'll need to replace the compressor, a clutch/coil kit isn't available for these.
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Customer: replied 7 years ago.

Thanks for the respose. Sounds like you agree with my conclusions that the clutch coil is bad.


However, I hate to hear there exists no clutch coil repair kit available. If so many coils fail, I would think there would be an after market clutch coil repair kit unless of course, rebuilding the clutch coil is too time comsuming or requires expensive clutch disassembly tools. Any thoughts?


Anyway thanks.



Rebuilding the clutch isn't that time consuming, and if you are able to find a clutch for it the compressor would need to come off of the truck to do it. I haven't searched for an aftermarket kit, being from a dealer you rarely use aftermarket parts because of warranty and qaulity control issues. Quality on aftermarket electrical parts is mediocre at best.

I've just checked Autozone and Napa, and they don't list an available clutch kit for them either. I would definitely try your local parts stores and see if they can come up with anything before ordering a compressor.