a/c not working

99 Escort compressor not engaging (except every once in a while in the morning for a short while.) Checked the CCRM. Pin 21 has voltage, as does pin 22 when the air is off. When I turn it on, pin 22 goes to 0 volts. The
info I have says if pin 21 has voltage and pin 22 does not, then the computer has grounded the relay to prevent compressor operation. The computer is sensing an engine performance problem and will have to be diagnosed and repaired for clutch to work. The motor seems to be running fine.I did plugs,wires,fuel filter and fuel injector cleaner.No help. Any ideas what I should look at next?
Thanks in advance, Dave
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endorf wrote:

working...i followed the book's instructions and turned the a/c on MAX and the blower on high... had the key turned on to run or let engine run... then checked voltage to the wire going to the cycling switch on top of the accumualtor.. got voltage there.. then went to the CCRM(intergrated contol module) and had voltage to the pink/lt. blue wire at pin No. 21.. the book says that you have to remove the RED wire to pin No. 22 (witch is probably an error as the RED wire is on Pin . 24. i cut the wire and the fan came on, the clutch then engaged.... it says if you then get voltage that it is either the Throttle Position Sensor bad giving the PCM(power control module) a signal to cut off the a/c or its the Engine Temp.. Sensor(the one with two wires attached to it) that gives the PCM the reading of high engine temp...(not the temp. sensor with one wire on it that goes to the Dash board telling you that you got a hot engine.)...... the book goes on to say that you disconnect these sensors and the a/c should now work(as the PCM is not getting these signals to turn the compressor off.... but it did not work for me.. i unplugged them both and it still would not come on.. i then tapped on the relay module and the throttle Pos. sensor and for some unkown reason i got back in car and turned off the engine and took out the key and then started the car up and the a/c came out cold... OK, its fixed, but how??? so i put the black/yellow wire coming out of the relay control module and put it back onto the rest of the a/c clutch wire( i originally had cut it so i could test for voltage there without listening for the a/c to click ON... well i though that was fixed.. no go.. NO AC.... i then take the wires off and double check the wires to the inside of the pins on the plug to the relay(all 24 of them ... i used straight pins, stuck it into the wire about 2 inches away from the plug to the relay and put the ohm meter for continuity, one wire to the straight pin and the other to the inside of the plug on the pin and they had continuity to each pin to wire.... i then used a small wire brush(with the key off) and brushed all the pins in the plug and the contacts on the relay to make sure there was no corrosion.. i did the same to the throttle Pos. sensor and also to the Engine temp. sensor. i also checked for continuity from it wires to the inside of the harness and there was continuity.. i took the throttle pos. sensor off and went to auto zone and they tested it... (not all auto zones test them) the first one i went to checked it and said it was bad on one side... i got another one and opened the box and it looked used.. i did not get it.. went to another auto zone and the guy told me he does not test them, he cant find the equipment..... i then say give one one.. he brings it out and its the last one also... i look at it and asked is it rebuilt as its all scratched up.. he checks it and says yes he can see it was used, but they dont take elect. parts back so he dont know.. i then go to napa and get one for $5 cheaper than auto zone and put it into the car and have the same problem... i did notice that i get voltage to the a/c line sometimes.. it seems that my contact points (if they have them in the relay module) is sticking.. but when you eigher turn the engine off or cut the RED wire to pin NO. 24 that the relay is released and the a/c works....after putting the wire back on and starting the car back up.... i also have a 96 contour and it might be similar to your car(its different than the 93 taurus, they have other cut off for the a/c.. i got the shop manual from Helm and got the electric/vacuum trouble shooting guide from them also... $65, $32 respectfully.. when i get to the heat of it, it refers you to the PCM book( the Power control Modue Troubleshooting book.. i went to the Helm web site and found that the book is in paper and cost $300 so thats out for me...
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endorf opined in

Then the answer might be to have the codes read out.
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Thanks. I was assuming the codes would only show up if the "service engine soon " light comes on. I guess that will teach me to assume. I'll have to find someone with a reader. Thanks again
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Someone else said to check the " wide open throttle" relay. Any idea where this is and what I am looking for?
Thanks, Dave
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endorf opined

Thats the relay you've been describing...in ccrm.
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