AC compressor clutch question

[Azrial89]

So i was recharging my system today hoping a recharge would engage the clutch, as soon as i started sure enough it kicked on. I used that whole can and still needed more, so i ran to the auto store to get some. came back home and continued to charge. I turned the car on and the clutch was still working great, then as i started recharging with the new can... nothing. I switched the system off then on again and the clutch engaged, but only when i go off to on. Any suggestions on what could be the issue?

 

[regan j]

what do your gauges read??

 

[QUIP'6']

So i was recharging my system today hoping a recharge would engage the clutch, as soon as i started sure enough it kicked on. I used that whole can and still needed more, so i ran to the auto store to get some. came back home and continued to charge. I turned the car on and the clutch was still working great, then as i started recharging with the new can... nothing. I switched the system off then on again and the clutch engaged, but only when i go off to on. Any suggestions on what could be the issue?

check your connection to the pressure switch and or the clutch. my pressure switch behind the condensor the pins needed tightened. it was causing an intermittent connection and causing the clutch to engage and disengage. the wire got hot to. when you turn it on becareful and try to wiggle the plugs on the switches and see if it changes

 

[Azrial89]

regan, which gauges are you referring to? thanks quip6 i will give it a try

 

[salvageV6]

The cycling switch can go bad.

And also you need the gauges for the A/C system to see if/why/when you need more or less freon and the low side high side pressure information for more accurate troubleshooting.

With an OHM meter KEY OFF test you can pop the round rubber plug off the cycling switch and measure accross the two terminals.

With the system at rest KEY OFF you should read a short accross the two pins when charged.

 

[mousemobile]

You may have overcharged it. The clutch drops out if the pressure may be too high or the system leaked.

Use gauges!

At the very least, a good way to check is feel the lines going in and out of the evaporator (at max). A good charge is when the lines are at the same temperature. If you have a contact thermometer, that is even better.

Believe or not, this is a procedure that I read in factory service manual. If you know how a refrigeration system works, it is a good reliable method.

I've done the calculations. I'm a mechanical engineer. The refrigerant changes phase while picking up heat from the passenger compartmen. The evaporator shouldn't change temperature.