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CCRM or pressure switch- 01 Escort

alfamike on Mon September 06, 2010 9:01 PM User is offlineView users profile

Year: 2001
Make: Ford
Model: Escort
Engine Size: 2.0
Refrigerant Type: R134a
Ambient Temp: 90F
Pressure Low: 100
Pressure High: 100
Country of Origin: United States

My niece brought over her Escort because the A/C stopped blowing cold. It has a full charge, & bypassing the low pressure switch on the accumulator did not cause the compressor to engage.

Therefore, I'm down to either the pressure switch (4 wire unit on the liquid line just before the OT) or the CCRM. I've read quite a bit about how troublesome the CCRM is in these cars, but I've been unable to find a way to positively diagnose a CCRM failure. The reason I'm hesitant to just buy another, in addition to the price, is that when I plugged in my scan tool (OTC Genisys), it said that the A/C pressure switch was off when I had the A/C controls set to Max A/C, fan speed high.

Looking at the wiring schematics on this, I'm certain that the Genisys is referring to the high side pressure switch as that is the switch that is wired into the PCM. I'm getting voltage to the pressure switch, & it has good ground. I tried jumping pins 1 & 4 together, but the compressor did not engage. These are the two leads on the pressure switch that go to the PCM. Was that the correct way to bypass the pressure switch? If it is, then that points to a faulty CCRM. Is there any other way to positively identify which of these components is faulty?

Thanks,

-------------------------
Michael Keith
Houston, TX

ACProf on Mon September 06, 2010 9:59 PM User is offline



Edited: Thu September 09, 2010 at 9:27 PM by ACProf

bohica2xo on Mon September 06, 2010 10:40 PM User is offline

You can just post it here, we have plenty of room.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

alfamike on Tue September 07, 2010 12:38 AM User is offlineView users profile

I did a little searching & found this test procedure & explanation of how the system functions: http://carfixonline.blogspot.com/2007/08/diagnostic-tech-99-ford-escort.html

I also found this one that's just more of a down & dirty voltage check: http://www.4s.com/Upload/Four%20Seasons/documents/Tech%20Tips/English/4S%20363%2097%20AND%20NEWER%20CCRM.PDF

These should apply to all 97 to 03 Escorts & presumably Mustangs as well.

I won't have another crack at the car until tomorrow evening. I'll follow up with my findings.

-------------------------
Michael Keith
Houston, TX

ACProf on Tue September 07, 2010 3:46 AM User is offline



Edited: Thu September 09, 2010 at 9:27 PM by ACProf

ACProf on Tue September 07, 2010 6:28 AM User is offline



Edited: Thu September 09, 2010 at 9:28 PM by ACProf

bohica2xo on Tue September 07, 2010 11:04 AM User is offline

Nice work Prof.

That will not "clog up" anything here. Clear pics & good info is always welcome.

I know guys like Chick will be thrilled. Well, Chick will be sorry he tossed all of those "bad" CCRM's he could have made a buck on... LOL

Thanks for posting that.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Tue September 07, 2010 4:31 PM User is offline

Why would anyone want to repair poor solder joints and clean a dirty normally closed contact when they could buy a new CCRM for only a couple hundred dollars?

Could be that by buying a new one, also has cold solder joints and NC contacts barely making contact and you would be out a couple of hundred dollars.

The problem with NC contacts, a relatively weak spring is used to keep them closed, spring is weak because the power of the solenoid in the relay has to overcome that spring pressure. If the NC contacts spend a great share of their life in the closed position, that little bit of a tad of wiper action when the contacts are opened and closed is not enough to keep them clean. So you the user, have problems, but yeah, it made it through the warranty period, least most of them did, and that is the only thing that counts.

I drill those rivets out with a #29 drill, then tap the holes for real 8-32 screws, they use rivets because they are not only cheaper, but they don't want you to look inside. You're suppose to buy a new one.

GM Tech on Tue September 07, 2010 4:46 PM User is offline

The 3 0r 4 I have done like this-- I meerly bypassed- looked up the wiring diagram-found the input and output wires for the a/c circuit and wired in parallel an external relay ($1.40 off ebay) and viola- all is fine-- when the ccrm can't do it- the external realy does--- takes about 10 minutes and much faster and easier than above method...don't eben remove the ccrm- just find the 4 A/c wires....

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

NickD on Tue September 07, 2010 5:54 PM User is offline

Quote
Originally posted by: GM Tech
The 3 0r 4 I have done like this-- I meerly bypassed- looked up the wiring diagram-found the input and output wires for the a/c circuit and wired in parallel an external relay ($1.40 off ebay) and viola- all is fine-- when the ccrm can't do it- the external realy does--- takes about 10 minutes and much faster and easier than above method...don't eben remove the ccrm- just find the 4 A/c wires....

Yeah, but if that car is ever shown, would lose points if the judges saw a relay hanging. Even some points if they saw screws instead of rivets. I could put new rivets in, have the tools for that, but know I will have to take it apart again for another problem.

Kind of a clever idea of jamming five relays and a couple of transistors in a box so you have to buy the whole box instead of just a relay.

alfamike on Wed September 08, 2010 12:13 AM User is offlineView users profile

Checked out the car this evening, & it is a faulty CCRM. Wow, what a surprise!

Auto Zone lists them for $105, but they're special order. I'm going to call a couple of parts sources I usually use to see what they have. From there, i'll let my niece decide whether she wants to buy a new one or have me attempt a repair. The reason I'm going about it that way is that if I attempt a repair & fail, the old unit may not be accepted as a core, & therefore, she'd be out the core charge as well. Also, I'm not exactly top-notch with a soldering iron. I'll let her decide if she wants to assume that risk.

-------------------------
Michael Keith
Houston, TX

NickD on Wed September 08, 2010 7:23 AM User is offline

If they want the core are you just buying one where someone touched up the solder and cleaned some of the dirt off that NC relay contact? And they want 105 bucks for that? Sounds like a good business to get into, especially if the user removes the part and brings it to you.

Did two relays for the FAA this last week a 3PDT and a 4PDT, one each one of the NC contacts wasn't bending backwards, just a few thousandths assuring good contact, with a fine needle nose pliers, just bend it forward a tad. Also the return spring from the armature goes to a tab, that tab is adjustable by bending to get more spring tension. For a 12V relay, should pull in between 6-7 volts, you adjust that spring so it does, can pull in as little as 3V, spring is way too loose.

Ford has been using this relay box for years, and for every different vehicle used a weird name for it, CCRM is another weird name. Recall one with a blown AC clutch drive PNP transistor in it, was a 5 amp size overloaded, put in an 18 cent 15 amp transistor in its place. Check all the relays, others are for fan control, and the all important fuel pump relay. This one has five relays, normally four, not sure what the fifth one is for.

ACProf, do you have a pinout drawing for this CCRM?

GM Tech on Wed September 08, 2010 10:17 AM User is offline

Nobody I know of would notice or even look at the core....why are you afraid to wire in a bypass relay? I'm telling you it is by far the simplest, easiest, least costly fix.....you can do it in under a half an hour the first time..all you need is a wiring diagram...If you buy a rebuilt one, or a used CCRM, you are most likely stepping right back into the same problem at some popint in time. By bypassing, you are redesigning their system, and forever fixing the problem-- That is why 90% of auto manufacturers offer independent relays, so that they are serviceable---just Ford chose to overdesign and thoroughly complicate this design. I say KISS keep it simple-- put it back to most common sense design.

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

ACProf on Wed September 08, 2010 12:58 PM User is offline



Edited: Thu September 09, 2010 at 9:29 PM by ACProf

alfamike on Sat September 11, 2010 3:21 PM User is offlineView users profile

Installed a new CCRM, & all is well. I went this route as opposed to a repair or a substitute relay mostly due to a lack of time on my part. Had I more time, I probably would have tried to repair it, & failing that, wired in another relay.

-------------------------
Michael Keith
Houston, TX

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