AC compessor not engaging

[Chris Boling]

'05 ST 4X2, 54,000 miles. Noticed the other day that the AC was not working. I hear a click, but the RPMS do not change. Looked under the hood, the clutch doesn't engage. Any known issues with this model? Beyond the fuse, where else should I look?





Thanks for any help.



Chris

 

[George C]

Could be you are low on refrigerant. Maybe you have a leak somewhere.



George

 

[Chris Boling]

Will it keep the compressor from engaging?

 

[George C]

Yes, I had the same problem. If the compressor engages while the refrigerant is too low or empty it will burn itself out. I guess it is not engaging to protect itself. Mine would just make the click you described and not fully engage.



George

 

[Jake Levin]

Mine did the same thing as well. The compressor would click in and then out rather quickly. drove me nuts. Took it in, had it tested for leaks and then recharged. Has been fine since

 

[farout squarecat]

How cold is it outside? AC is not supposed to work below a certain temperature.

 

[Dreman]

Most vehicles made in the last 25 years have a low pressure switch that cuts the compressor off if there isn't enough pressure in the system. I assume our Tracs are the same.



Sometimes there will be enough pressure to engage the compressor for a few seconds, but then kick off again when the compressor pulls the refrigerant out of the line and there isn't enough left to maintain pressure. Then when the system returns to normal, the pressure builds up enough to activate the compressor again. That's where you get the on-off-on cycle every few seconds.

 

[Chris Boling]

Will check, thanks for the help