no power to A/C compressor

[pete315]

I have my A/C system fully charged. I checked the #17 fuse circuit, fuse is good. I jumped the low freon plug on top of accumulator, still no power. I checked the wiring, no visible breaks. I ran a direct power source to the A/C compressor, kicks right on. I would leave it this way however the compressor clutch is constantly engage instead of cycling. The evaporator is actually turning to ice and I lose the air flow from the vents. I know there is a relay box just under the fan safety cover on radiator support, not sure if that could be the problem. I tried tapping it with no luck. anyone else ever come across this problem? any help would be great.

 

[projectSHO89]

Which car in your signature?

 

[pete315]

93 sho.

 

[pete315]

what makes a/c compressor cycle

with a fully charge a/c system, the clutch is not always engaged on the a/c compressor. what part causes the clutch to cycle? is it the switch on top of the accumulator? I know that will send no power to the compressor if it's low on freon. Does this part also control the clutch and when to engage and for how long?

 

[projectSHO89]

Threads merged. Please keep posts on the same subject in the same thread.

 

[projectSHO89]

The low pressure cycling switch, in series with the mode switch on the dash (or EATC) sends power to a solid state relay inside the CCRM module. As long as the PCM is NOT sending an inhibit signal to the CCRM, the relay will energize and supply power to the clutch coil.

See my posts in the stickied thread above regarding IRCM/CCRM details.