A/C...CCRM issue?

[randy'sho]

having an ac issue with my newly acquired 93 atx....freon is fully charged, no power going to ac compressor from ccrm when max ac is on! i ran a 12v hot wire to compressor and it kicks on perfect ( so i know the compressor is good).......but no cold air comes out....ac lines dont even get cold! try to cross my low pressure switch and nothing happens. Pretty sure my ccrm is bad, but not sure what else could be the problem!

 

[rubydist]

first, check to see if the signal power is getting to the ccrm telling it to turn on.

if so, check to see if the ccrm has power on the correct pin on the output side.

if so, check to see if the power is appearing at the other end of the wire at the a/c clutch.

I have had failures in all 3 locations.

 

[randy'sho]

first, check to see if the signal power is getting to the ccrm telling it to turn on.

if so, check to see if the ccrm has power on the correct pin on the output side.

if so, check to see if the power is appearing at the other end of the wire at the a/c clutch.

I have had failures in all 3 locations.

ok...i have checked to see if i had any power out of ccrm on pin 23 and there was nothing! i would have thought that when i ran a 12v wire to compressor and it came on that i would have seen cold air at that point, but i did not

 

[probe_racer]

ok...i have checked to see if i had any power out of ccrm on pin 23 and there was nothing! i would have thought that when i ran a 12v wire to compressor and it came on that i would have seen cold air at that point, but i did not

have you checked to make sure the blending door is working,??

Do you have an A/C manifold gauge to check the refrigerant pressure levels?

I had this issue in a pontiac and even though the a/c was working the blending door did not move due to a bad vacuum line so it was always blocking air flow through the evaporator. otherwise i think you A/C has a low charge of refrigerant.

 

[randy'sho]

have you checked to make sure the blending door is working,??

Do you have an A/C manifold gauge to check the refrigerant pressure levels?

I had this issue in a pontiac and even though the a/c was working the blending door did not move due to a bad vacuum line so it was always blocking air flow through the evaporator. otherwise i think you A/C has a low charge of refrigerant.

Yes charge is in perfect range, don't think it is blend door because I have no cold ac lines under hood at all when compressor is engaged

 

[zak]

I had a pin that was corroded on this circuit, wasn;t at the CCRM but at a connector inbetween the CCRM plug and the plug on the compressor clutch - cleaned it and the AC has worked perfectly since. This was on a 95 MTX though

 

[probe_racer]

what are your pressures on low side and high side of A/C when the compressor is running?

if the lines don't get hot or cold when the compressor clutch is engaged and compressor is running then the only thing i can think off is that the compressor is blown, and is not able to compress and move refrigerant.

to really know if AC is fully charged you need the A/C manifold tool with gauges, the reading is a lot different when running than when system is off.

good luck, keep us updated.

 

[rubydist]

sounds like you still have multiple issues:

did you check for voltage on the signal (input) pin of the ccrm? it may be that the pcm is bad or that the wire between the pcm and ccrm is bad. if there is no signal at the ccrm, it would logically follow that there would be no output from the ccrm.

if the signal voltage is there, then the ccrm is bad.

as far as the a/c actually doing anything when the compressor is running, you need the gauges and check as probe-racer described above.

 

[projectSHO89]

There is a complete description of the CCRM and how it works in a sticky in the electrical section that I wrote a few years back.