my a/c compressor locked up on me

Good morning,

I do not agree. You can have a bad fan clutch but it will not cause the compressor to lock. There are safety switches on the system to turn off the compressor clutch when the pressure gets too high.

https://www.2carpros.com/articles/how-a-car-air-conditioner-works

I am wondering if he did not add the oil to the replacement compressor before he installed it. That would be like running an engine without oil.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

https://www.2carpros.com/articles/replace-air-conditioner-compressor

Who provided the parts?

Roy

I took my truck to an air conditioning shop that specializes in this kind of work and they provided the condenser,evaporator,liquid line with orifice tube inside and I provided the aftermarket compressor. The compressor came with oil inside from the manufacture. Mechanic was telling me to take it to the dealer so they can check if the computer has previous codes of fan clutch intermittently working because if it doesn't work it will damage my compressor. Do all vehicles have those switches to keep the compressor from locking up? And if so. I wonder why this specialist mechanic told me to get my fan clutch checked at dealer.

The system had a pressure switch to protect the compressor from developing too much pressure. If it exceeds 375 pounds, it will shut off the system.

If they specialize in A/C, then they should be able to do this as it is part of the system.

Below is the description of the clutch.

Roy

FAN DRIVE VISCOUS

DESCRIPTION
5.9L DIESEL ENGINE (ELECTRONICALLY CONTROLLED FAN DRIVE)


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The electronically controlled viscous fan drive is attached to the fan drive pulley mounted to the engine. The coupling allows the fan to be driven in a normal manner. The fan speed is controlled by the electronic control module.

OPERATION


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The Engine Control Module (ECM) controls the level of engagement of the electronically controlled viscous fan clutch by monitoring coolant temperature, intake manifold temperature, air conditioning pressure and transmission oil temperature. Based on cooling requirements, the ECM sends a signal to the viscous fan clutch to increase or decrease the fan speed.

Fan speed is monitored by the ECM. Fan speeds above or below a calibrated threshold will set a DTC. Circuit concerns will also set fan clutch DTC's.

It sounds like the fan clutch does have in involvement to the A/C system but since it has a pressure switch to protect it, It shouldn't lock up my compressor. My previous newly installed compressor was only used 5 times for under 30 minutes each time and it developed an oil leak and pulley and clutch assembly became very loose and sloppy. I'm glad to hear that my fan clutch did not cause that problem nor will it ruin this new compressor that just got installed. What does DTC stand for?

DTC is a fault code that is stored in the system.

Roy

Thank you Roy. Your professional insight was very helpful for me. I learned a lot.

You are welcome.

Always glad to help.

Roy