A/C help?

[Dan H]

So the AC worked fine Wed, didn't work on thursday. The compressor is not turning when the A/C is "on", the engine speed/load doesn't change when you turn the A/C on or off.

Any suggestions? Is it just a bad compressor clutch, or coul it be a problem with the environmental control?

Any help appreciated.

 

[rangerj]

The gap between the clutch surfaces should be .025 to .035. Check the gap. If it gets too wide the clutch coil can fail to pull the surfaces together, ie not engage.

Next, if the gap is OK jump the low pressure switch connection and see if the clutch engages. If it does you may have low pressure from a need for additional refrigerant charge. If it does not your clutch coil may have failed.

You can connect battery voltage to the clutch coil to see if it become a strong electromagnet. If it does not, it has failed. If it does, look for a wire or connection problem.

If you have access to A/C gauges check the pressures. It takes about 20lbs to activate the low pressure switch.

Just some thoughts, rangerj

 

[Dan H]

The AC was ice cold two days ago, so I doubt that it is low on refrigerant.

The clutch is definitely not engaging, I will check the gap.

How do I jump the switch to see if it engages (I'm assuming that this is to check if it is an issue with the EATC)?

Thanks