A/C compressor clutch not engaging

[chimp5150]

Hi all! Got a problem with my air conditioner compressor clutch on my 90 Sable 3.0 L. I posted here because Sable and Taurus are almost identical and because I have heard the Sable forum doesn't get much response. I have just replaced the compressor but the clutch will not engage with A/C on max so I can't charge the system. I tested the pressure switch and it is good. I disconnected the connector from the clutch and checked for voltage but there was none. Have checked fuse 17 which is for clutch but it is good. Could it be the Integrated Control Module? If so, where is this thing located? Are there any fusible links to check in this circuit? If so, where are they located?

Thanks in advance for any help!

[sahib]

Have you checked for voltage to one side of the pressure switch? I believe voltage goes to the switch and then through if the pressure is up. If it is not up the switch will be open and the voltage stops and the clutch is deprived. It's been a few years since I've fooled with this so am not real up on procedure. I believe you have to unplug the connector to the switch and jumper the terminals in the harness connector while recharging. You should have replaced the accumulator and evacuated the system before recharging. Have you retrofitted to R-134 or are you using R-12?

[chimp5150]

Hey Sahib, thanks for the reply! I have checked for 12 volts on one side of the pressure switch and it is there. I have also tested the switch by adding r134, and watching the switch close with a meter. I then let some out and the switch opened. The next thing in line in the circuit diagram is the "integrated control module." The pressure switch feeds into this, and the clutch coil is connected to its output. It has to be either this module or the wiring associated with it. I can get another module at Autozone but here is the problem: I don't know where it is located on the car. Haynes completely ignores the subject. There is a huge connector that connects to the fire wall right behind the computer diagnostic port. It has what looks like a removable module in line with it. I am thinking this may be the module I am looking for. When I get the new one from Autozone I will know for sure.

The system has been evacuated but I did not replace the accumulator. Should I go back and replace it? What will happen if I don't? Also, I am converting from R12 to R134.

This all started when we took it to a shop and they told us the compressor was seized and it would take $1000 to fix it. I decided to replace the compressor on my own. I shouldn't have taken their word it was seized because now it looks like an electrical problem. I guess if it was seized it could have damaged this control module.

Anyway, thanks for the help! Can you think of anythng else I should do or give some advice on the accumulator? I can replace it just didn't know if I needed to. Also, is there a relay or fuse or something in the circuit somewhere that I don't see in the Haynes manual?

Thanks!

[chimp5150]

update: I finally found the "integrated control module." It is under a plastic shield just above the radiator. The circuit on both sides of this thing tests good so I am going to replace it. It is apparently just a bunch of relays for various things in one package. Costs $70.00. Sheesh! Will post back results later.

[sahib]

Ah! You found it. Good! I thought that might be the critter but wasn't sure. As far as the accmulator replacement, it is recommended that you change it out any time the AC lines have been opened. There is a packet of desicant in the bottom of this unit that absorbs any moisture that may be in the system. Moisture in the AC system is not a good thing. I have placed it under a heat lamp for a day or so with pipes open and placed so that any moisture that may be trapped in the unit can escape and put it back in without any adverse effects. Maybe I got lucky. You'll have to decide for yourself what is best for you. I think that ICM has something to do with taking the AC off line when more power is required by the car. Hope you get your problem solved.

[millerl513]

Originally Posted by sahib

Ah! You found it. Good! I thought that might be the critter but wasn't sure. As far as the accmulator replacement, it is recommended that you change it out any time the AC lines have been opened. There is a packet of desicant in the bottom of this unit that absorbs any moisture that may be in the system. Moisture in the AC system is not a good thing. I have placed it under a heat lamp for a day or so with pipes open and placed so that any moisture that may be trapped in the unit can escape and put it back in without any adverse effects. Maybe I got lucky. You'll have to decide for yourself what is best for you. I think that ICM has something to do with taking the AC off line when more power is required by the car. Hope you get your problem solved.

hi chimp-----i have a '92 taurus with a similar problem, but i have no voltage on either side of the connector plug--fuses are ok---i could go fishing and either replace the icm or the switch at the dashboard---any thoughts???

[Froze_Tread]

Reciever driers are recommended by most to be replaced whenever the system is open. It takes only 30mins when the system is open on a normal 20% humidty day to saturate it. That said Ford recommends only replacing it when thier is reasone to such as compressor sent a bunch of metal through the system plugging the oil hole in the drier, system was left open for way to long. and of course the system is not performing well. Moisture will ruin your ac compressor and other compents but i usually only replace if need be. And i always told that u cant remove moisture from a desacnt bag but who knows. Did u ever get yours running??

[ratsassracing#2]

wish someone could post the anser to this post same problem w/same car 92 tarus

[stang805]

the eaisest way to figure out where the prob might be is to jump the 2 wires in the low pressure switch connector woth somthing, car running, A/C on max, if the compressor runs, you either have a bad pressure switch or low charge, the "module" is nothing more than a relay, if you listen you should be able to hear it click when you jump the connector, if you can hear it and the compressor still doesnt run, check for voltage at the clutch coil, if there is none, start checking wires for continuity, and when you open the system you really should replace the accumulator, and dont forget to charge with oil too, or all that work will be for nothing

[stang805]

btw, another prob you might have is make sure you do the complete retro before you switch to r134a, r12 systems dont always respond well to the new refrigerant, charge to 80% of the r12 capacity with 134a

[ratsassracing#2]

mine has no power to pressure switch or compressor ,fuse is good