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the pcm uses the pressure switch as an input, and in turn will ground the coil of the relay, based on what i see in your video, you have verified that the ccrm is faulty internally. when u applied power to the coil the lamp should have lit and the relay should have held.
no more tests you verified ccrm functionallity ,dealer only i believe for a good qualityunit, but i dont think that they are that expensive search (2001 mustang ccrm) in google then go to shopping, you will see many listed from $60-%100 for an aftermarket or refurbished unit, you could depin those circuits and just splice in a regular relay.....but once something in the ccrm starts going bad, the rest of the realys inside are not far behind, so then your fuel pump, and cooling fans are destined to stop sooner then later. and thats alot of wiring to add in
But I DID find a *really* janky solder joint which happens to correspond to the output of the AC clutch relay at pin 23:
I'm going to reflow that. My concern is there is a reason it was janky in the first place; can't tell if has been getting too hot. The PCB isn't scorched. I'll clear the old solder and maximize contact between that leg of the relay and the solder land before re-flowing. There is also an electrolytic capacitor on the board I'm going to shotgun. It's a good quality part, but is now going on 15 years in a harsh environment, and the voltage spec seems lower than it needs to be at 10V. It's a 12V system and without a full schematic I don't know what the drop is in the circuit in which that cap sits, but I'm going to drop a 16V part in there. My hunch is that cap never sees anything near 10V, but because it's a 12V system there is always potential for that cap to see 12V in a fail state, so that's why I'm going to put something in that is equal to or greater than 12V.
Any other suggestions?
Last edited by sweetbeats; 08-09-2015 at 08:55 AM.
nice, i have not yet disassembled a ccrm, but its not unlike the other solder joint related issues that the 97-03 f150's had with its clusters and overhead displays, both are easily fixed by reflowing the joints. that connection pictured will cause a volt drop IMO so reflow and retest and let me know if it fixes it, if so ill add it to my list of stuff i can pull apart and fix as opposed to replacing
Congrats!! Hard to believe you two pinned it down to the component level! That's pretty old school.
You sure learn how things work when you follow it all the way to the problem. Thats a great ending, instead of just replacing stuff til it works, and a lot cheaper.
I have a new problem...it's really cold inside this car...
lol awesome! glad u fixed it, and the best part is..... unlike most people who dont repair cars for a living you did it without throwing parts at it till u guessed right. you would make an excellent diagnostician
Thanks guys! I can tell you I'm pleased...and chilly. Lol
Best part is this is my fiancée's daily driver and we've gotten into the 100s here recently. I'm excited to tell her she finally has AC for the first time since owning this car. Her ex never took care of it for her.
Can't tell you how much I appreciate your help and patience, jwog666...it literally wouldn't have happened without ya!
The tail on the AC relay related to that bad solder joint felt brittle when I bent it over to make contact with the land which I enlarged. I'm going to order a replacement relay, because it's quite possible that terminal may go bad at some point.
Next up, replace the alternator, fix a minor oil leak in the plumbing to the supercharger, replace some damaged speakers, try and figure out why the suspension is so damn *creaky*, and load the MAFturburner software and read up on that thing. I'm convinced my fiancée's ex threw her money away having it "tuned" by somebody locally, but anybody can smell the car is running rich, and on top of it the "tune" was done with IACV faulty, vacuum hoses disconnected, and an air filter that was totally loaded with dirt. And the ex had her convinced nobody could work on cars like he could. I'm no expert, but geez. I digress. Does anybody know a trustworthy tuner for this car anywhere near Portland, Oregon? I'd take the car a ways to have it done right if it was somebody that understood this car, the setup and the Sean Hyland Motorsport Zone 5 MAFterburner+ that's installed. Maybe that's a topic for a whole new thread.
Anyway, kinda getting attached to this thing. Can you tell?
08-08-2015, 09:37 PM
