A/c help please

Joe, if you have a Haynes manual, check the electrical system section in the back. They have a decent schematic back there.

The system is complicated enough that I wont be able to articulate the entire set-up (the PCM and CCRM muddy the waters a bit in terms of circuit pathways). Maybe one of the smarter guys can articulate what I cant (or post a diagram).

EDIT: I had some crap typed up with colors of wires, but I just noticed what appears to be a color discrepancy in the link I posted and the Haynes schematic, so I wont post colors of wires.

I'd check the WOT stuff first. And check that schematic in your manual - it should clear things up in your mind about the pathways. I'd just confuse you more if I wrote about it.

Good luck and bump for one of the wiring gurus to help ya out.
 
Thanks for all the help guys.
Hissin, I think you are 100% correct in saying it is the CCRM WOT relay. I have been researching and have found several other ford owners with the exact problem. I'm going to run a few more tests on the CCRM and hopefully get it replaced. I'll keep everyone updated.

Also, would anyone know the safest way to power the compressor just to see if it kicks on? A wire from the battery and a wire to ground just run to the compressor? I realize this isn't the smartest idea but I just want to see the damn thing spin! How would I know which wire goes to which prong?

Thanks again
Joe
 
Synned said:
Thanks for all the help guys.
Hissin, I think you are 100% correct in saying it is the CCRM WOT relay. I have been researching and have found several other ford owners with the exact problem. I'm going to run a few more tests on the CCRM and hopefully get it replaced. I'll keep everyone updated.

Also, would anyone know the safest way to power the compressor just to see if it kicks on? A wire from the battery and a wire to ground just run to the compressor? I realize this isn't the smartest idea but I just want to see the damn thing spin! How would I know which wire goes to which prong?

Thanks again
Joe
Joe, this is a question for JRichker or one of the other guys who play with these sorts of things. I have never (in essense) bench tested a compressor via applying fuse battery power and ground to it. I would note that it appears to me that even the ground is computer controlled and I HATE to start jumping circuits when a PCM is involved.

If you do anything like this, I think someone might suggests disconnecting the electrical connector at the compressor and applying your jumpers directly to the compressor (so you dont backload the existing circuits with power and ground from the jumpers). But I can't recommend how to jump the compressor (or even doing it in the first place) since I havent done it and dont pretend to have a solid handle on every pathway in the system.

Bump for you.
 
Here is a detailed procedure to go through that I found, maybe helpful for anyone else having this problem. Almost sure its the CCRM now.

If you still need help let me know i have my book wiring schematic book at home.. Looking at the schematic get a test light and see if with the a/c in the on position you have power at the low pressure switch ( with it unplugged it will only have power on one side of the plug) (the one that screws onto the accumulator next to the firewall on the passenger side) Make sure the engine is running .. ASSUMING it has not gotten a leak and all the freon has leaked out you should then have power on the other side of the switch when you plug it back in.. IF NOT then you either have a leak that leaked all your freon out OR you have a bad low pressure/clutch cycling switch.. IF you have power there then go to the pressure swith with 4 wires on it.. that screws into the a/c line by the radiator on the passenger side.. Unplug it with the a/c still in on position and car running.. (make sure you plugged the low pressure switch back in)... There should be four wires.. one should be dark blue with a yellow stripe /tracer on it.. see if it has power... IF it does then plug switch back in and see if the dark green /orange wire has power on it(you will have to either skin the wire a little or pierce it with your test light ... IF YOU HAVE POWER AT THESE PLACES then you either have a bad ccrm module OR a bad compressor clutch .... To test the compressor clutch unplug the compressor and see if you have power on the black/yellow tracer wire in the two wire compressor plug... IF you have NO power and you have tested thru the circuit like i have explained then your ccrm module is bad... IF you have power at the compressor clutch then either the compressor clutch is bad OR you do not have a good ground.. (the other wire on the plug). In which case i can lead you thru testing the ground if necessary... All in all the most likely culprit is the ccrm module... But i like to go by the words of my Dad (electrician for 40 plus years) TEST ,,DON"T GUESS!!
 
Well I have sort of bad news. I'm at work, with my new relay and decided to try it out. I unplugged the old ccrm, plugged in the new and kicked it up. Turned the air on and the compressor didn't budge. Well I'm pretty upset, I got a deal on the CCRM from a mechanic that I know brand new from a ford dealer. Well its still not working, I didn't get a chance to do any further testing, to even see if there is juice at the compressor.

The only other thing I think could be kicking it off is that the ccrm or computer I'm not sure which is seeing a performace problem and not letting the a/c turn on. I hope this isn't the case, I do have a slight misfire though. There aren't any codes though.
Besides that, I guess a wiring problem and a fuse are the only other culprits. Later I will try jumping both pressure switches and trying it with the new ccrm.

Wish me luck guys!
EDIT: Come to think of it, maybe I should have unplugged the battery for a minute or two...
 
Anyone have anything to add? Today I tried to get it running again, hooked up the new CCRM, still no juice at the compressor. I tried jumping the low pressure and high pressure switches, still no voltage at the compressor. I then unhooked the battery so the computer would reset itself and all the performance problems would be gone in case that was whats stopping the a/c.

I really don't know what to do anymore. The high pressure switch looked like it was going to anohter switch under the airbox, could this have gone bad?
I need guidance!
 
Are you checking the switches to see if they have input going into them? If they dont, jumping a switch that has no juice wont help.

That's all I can think of at this point, though it's something you probably already tested (you've gone around so much with this that it doesnt hurt to ask again).

Good luck Joe.
 
Hey bud, sorry your having such a tough time. like I said before, if you don't have enough or you have too much freon in the system the compressor wont kick on, you could be jumping things for days, please don't overlook this. also, as I said before, look for leads at the expansion valve, very common thing to leak, and if it did leak out the compressor wont work. just give it a try and make sure thy system is properly charged. at least recharge it for a sec to specs and see if the compressor is working, if it is you need to find a leak, not very common for the compressor to just stop working although it does its more common you just have a leak.
 
Raginstang said:
Hey bud, sorry your having such a tough time. like I said before, if you don't have enough or you have too much freon in the system the compressor wont kick on, you could be jumping things for days, please don't overlook this. also, as I said before, look for leads at the expansion valve, very common thing to leak, and if it did leak out the compressor wont work. just give it a try and make sure thy system is properly charged. at least recharge it for a sec to specs and see if the compressor is working, if it is you need to find a leak, not very common for the compressor to just stop working although it does its more common you just have a leak.

So what you are saying is that even if the compressor has voltage, if there is too much freon or too little it won't kick on? Because the problem is it doesn't have voltage at all. I thought that if the low pressure switch was jumped, along with the high pressure switch that would eliminate anything that would cut voltage from the compressor due to charge.

When I try to measure the freon, it shows 100psi. I was told it would say very high if the compressor wasn't turning.

Thanks guys
 
Joe, you're right. The switches are safeguards and by bypassing them, you are creating a conduit for the electrical signal to try to reach the compressor. The compressor in a system with no refrigerant whatsoever can be turned on if switches are jumped. This is how one starts to charge an otherwise empty system (or one that doesnt have enough refrigerant in it to even kick on).
 
PROGRESS!

So I was following the guide, and I was at this part:

9. CCRM Output To PCM
Disconnect CCRM pin No. 22 (Pink/Yellow wire) from connector. If A/C clutch does not
engage, go to next step. If A/C clutch engages, repair WOT cut-out and ECT. See the
appropriate G-TESTS W/CODES article in the ENGINE PERFORMANCE section.

I cut the pink wire, and success! When I tried the air, the compressor goes on for about 3 seconds, then cuts off, and goes back on, and cuts back off.

Is this supposed to happen? Is it 'warming up'? I didn't want to leave it running.

So it's not the WOT switch, so I guess its the ECT problem. I don't have any codes, and the ECT sensor is about a year old.

So should I leavfe it running and see what happens?
 
Synned said:
PROGRESS!

So I was following the guide, and I was at this part:

9. CCRM Output To PCM
Disconnect CCRM pin No. 22 (Pink/Yellow wire) from connector. If A/C clutch does not
engage, go to next step. If A/C clutch engages, repair WOT cut-out and ECT. See the
appropriate G-TESTS W/CODES article in the ENGINE PERFORMANCE section.

I cut the pink wire, and success! When I tried the air, the compressor goes on for about 3 seconds, then cuts off, and goes back on, and cuts back off.

Is this supposed to happen? Is it 'warming up'? I didn't want to leave it running.

So it's not the WOT switch, so I guess its the ECT problem. I don't have any codes, and the ECT sensor is about a year old.

So should I leavfe it running and see what happens?



It looks to me like the pink/yellow wire is for the WOT relay (it's the wire from the PCM that energizes the coil in the WOT relay and kicks the AC off. It should be a ground pulse when the AC is supposed to be shut off, and otherwise the wire should be dead).

WIth the wire now cut, if you put your meter on the end that goes back to the computer, does it read any resistance? If it does, that indicates a short and could be the issue.

Otherwise, cycling like you have indicates a low charge in the system. That's not to say that there isnt something else going on with all the troubleshooting you've done - just general info. I'd check pressures.

Good luck.
 
HISSIN50 said:
It looks to me like the pink/yellow wire is for the WOT relay (it's the wire from the PCM that energizes the coil in the WOT relay and kicks the AC off. It should be a ground pulse when the AC is supposed to be shut off, and otherwise the wire should be dead).

WIth the wire now cut, if you put your meter on the end that goes back to the computer, does it read any resistance? If it does, that indicates a short and could be the issue.

Otherwise, cycling like you have indicates a low charge in the system. That's not to say that there isnt something else going on with all the troubleshooting you've done - just general info. I'd check pressures.

Good luck.

Yup, it is low on freon.
Well, I really don't care if it's just the WOT cut off- I don't need that and it can be left off.
The thing I'm wondering is, could the computer want to ground that wire for any other reason? Performace problem? ECT sensor?
I have no codes, but I wonder...
I'm just happy I figured it out for now.

BTW, thanks for all the help you have been hissin. :SNSign:
 
Synned said:
Yup, it is low on freon.
Well, I really don't care if it's just the WOT cut off- I don't need that and it can be left off.
The thing I'm wondering is, could the computer want to ground that wire for any other reason? Performace problem? ECT sensor?
I have no codes, but I wonder...
I'm just happy I figured it out for now.

BTW, thanks for all the help you have been hissin. :SNSign:
The WOT wire comes from the computer itself (inferred from the TPS reading). So as long as the TPS is ok and not shorting VREF to signal return, that shouldnt be it.
I would do a couple more minutes of testing (I know you're sick of it) and see if the computer is even putting ground to that cut wire, or if it's the WOT relay itself that's energizing on its own. If the wire isnt normally grounded, you can figure the wiring and components are sound, and it's the WOT relay. I figure you might want to know the real cause at some point..............

I dont know if compressors can have an issue trying to spin with the clutch engaged at 6K RPM. You really could wire in a SPDT relay as a stand-alone relay in lieu of the stock integrated relay in the CCRM. You would have to mess with 3 other wires. If you lived close, I'd have ya come by and it would take all of 5 minutes to do and be done in such a way as to have full reverse compatibility in case you want to go back to a stock appearance/function.

But that's all if the issue is just with the CCRM's WOT relay only (if you have a wiring issue, the new relay will probably allow the existing issues to reoccur).