My A/C compressor locked up on me

Tiny
ADIAZ260
  • MEMBER
  • 2006 DODGE RAM
  • 5.9L
  • 6 CYL
  • TURBO
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
I just purchased a new aftermarket air compressor and had it professionally installed about 200 miles ago. Only used the a/c 4 times and my a/c compressor locked up on me. At first I thought it was a cheap faulty air compressor. I had to tale it back to mechanic and have an entire new a/c system put in. Mechanic tells me that I may have an intermittent bad fan clutch that could lock up my air compressor and if it does I ll need a whole new system again( air compressor, condenser, liquid line, and evaporator) How can I or a shop diagnose an intermmetent bad fan clutch? Its working fine right now
Thursday, June 18th, 2020 AT 6:14 PM

7 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
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

Was this
answer
helpful?
Yes
No
Friday, June 19th, 2020 AT 3:40 AM
Tiny
ADIAZ260
  • MEMBER
  • 4 POSTS
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.
Was this
answer
helpful?
Yes
No
Friday, June 19th, 2020 AT 6:21 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
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)

imageOpen In New TabZoom/Print

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

imageOpen In New TabZoom/Print

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.
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Saturday, June 20th, 2020 AT 3:19 AM
Tiny
ADIAZ260
  • MEMBER
  • 4 POSTS
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?
Was this
answer
helpful?
Yes
No
Saturday, June 20th, 2020 AT 11:24 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
DTC is a fault code that is stored in the system.

Roy
Was this
answer
helpful?
Yes
No
Saturday, June 20th, 2020 AT 11:32 AM
Tiny
ADIAZ260
  • MEMBER
  • 4 POSTS
Thank you Roy. Your professional insight was very helpful for me. I learned a lot.
Was this
answer
helpful?
Yes
No
Sunday, June 28th, 2020 AT 3:06 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You are welcome.

Always glad to help.

Roy
Was this
answer
helpful?
Yes
No
+1
Sunday, June 28th, 2020 AT 3:50 PM

Please login or register to post a reply.

Related Air Conditioner Compressor Locked Up Content

VIEW MORE