CCRM for my 1989 SHO

[Rich G]

Recently my SHO started to overheat. I checked it out and the cooling fan was not coming on.
I wired the fan directly to the battery and it ran fine. Had my mechanic check the car out and determined the ccrm is faulty.
Mine is E9DF-12B577-AA with the M on it. Doing some checking I found a couple places to get one.
Auto ECMs in Pennsylvania rebuilds them, but a bit pricey. And a new aftermarket one on Ebay sold by SATP2012. Made by SMP # RY533.
Which matches my part number. Has anyone here used either of these sellers or parts? I would rather not buy an untested used one.
This one seems to be the hardest one to find.

Thanks, Rich

 

[Irish Pride]

Better off buying a good used Ford one imho. I may have an M code in my parts stash. I'll let you know later tonight.

I'm the mean time, try giving the CCRM several good whacks with the plastic handle on a large screwdriver. The CCRM is just a box filled with relays. It is very common to free up the stuck relay by giving it a few good hits.

-Chad

 

[Irish Pride]

PM me if interested.

-Chad

 

[Rich G]

Hi Chad, Thanks for the tip. I will give it a try over the weekend and see if it works.

 

[Greg Corcoran]

Recently my SHO started to overheat. I checked it out and the cooling fan was not coming on.
I wired the fan directly to the battery and it ran fine. Had my mechanic check the car out and determined the ccrm is faulty.
Mine is E9DF-12B577-AA with the M on it. Doing some checking I found a couple places to get one.
Auto ECMs in Pennsylvania rebuilds them, but a bit pricey. And a new aftermarket one on Ebay sold by SATP2012. Made by SMP # RY533.
Which matches my part number. Has anyone here used either of these sellers or parts? I would rather not buy an untested used one.
This one seems to be the hardest one to find.

Thanks, Rich

Just something to consider - I had a "bad" CCRM that would not turn on the fan. Same test - jump from the battery made the fan work. After a used one, one from NAPA, and having mine rebuilt to no avail, I happened to mention it to a retired Ford mechanic. He reached down to the back of the engine, disconnected the coolant sensor and the fan came on. (Must be part of the limp home mode?)

Apparently it is not uncommon for the temp sender to shift cold, so it does not give a reading high enough to cause the ECM to call for the fan, and the CCRM is never asked to trigger the fan. A new coolant sensor fixed it. (I also have a few D code CCRMs here if anyone needs one ;-) )

 

[Rich G]

Just something to consider - I had a "bad" CCRM that would not turn on the fan. Same test - jump from the battery made the fan work. After a used one, one from NAPA, and having mine rebuilt to no avail, I happened to mention it to a retired Ford mechanic. He reached down to the back of the engine, disconnected the coolant sensor and the fan came on. (Must be part of the limp home mode?)

Apparently it is not uncommon for the temp sender to shift cold, so it does not give a reading high enough to cause the ECM to call for the fan, and the CCRM is never asked to trigger the fan. A new coolant sensor fixed it. (I also have a few D code CCRMs here if anyone needs one ;-) )

I had a chance to check the car today. Drove it till the temp came up to the O on the temp gauge of NORMAL.
Figured the fan should have been on by then. It wasnt. As suggested before, I tried tapping on the box and the fan still didnt start. I turned on the A/C and the fan kicked right on!
If there is only one relay in the CCRM for the fan, then I guess the CCRM is good. Or Are there 2? One when the A/C is running and one when its not on?
Thanks for the tip on the coolant sensor! Greg. Thats easy enough to check. I wasnt thinking of checking that as my dash temp gauge is operating normally. Can it still work the gauge but not send a proper signal to the CCRM? Was your gauge working correctly?

Thanks, Rich

 

[Greg Corcoran]

On my '95 there are 2 sensors - one for the gauge which has a single post (threaded I think?) and one for the ECU which is 2 pins. My gauge always worked, it was the 2 pin one that fed the ECU that had drifted. And yes under most situations I am aware of the AC engaging will ask the CCRM to run the fan. Running the AC was my work around, as the '95 has two fans or a two speed fan (can't remember which) so the other CCRM relay would engage the other fan/ fan speed.

 

[Rich G]

On my '95 there are 2 sensors - one for the gauge which has a single post (threaded I think?) and one for the ECU which is 2 pins. My gauge always worked, it was the 2 pin one that fed the ECU that had drifted. And yes under most situations I am aware of the AC engaging will ask the CCRM to run the fan. Running the AC was my work around, as the '95 has two fans or a two speed fan (can't remember which) so the other CCRM relay would engage the other fan/ fan speed.

On my '95 there are 2 sensors - one for the gauge which has a single post (threaded I think?) and one for the ECU which is 2 pins. My gauge always worked, it was the 2 pin one that fed the ECU that had drifted. And yes under most situations I am aware of the AC engaging will ask the CCRM to run the fan. Running the AC was my work around, as the '95 has two fans or a two speed fan (can't remember which) so the other CCRM relay would engage the other fan/ fan speed.

I gave it another try today. Got the engine hot and disconnected the temp sensor wire. I waited till the needle was almost in the red. The only thing that happened is the temp gauge went to cold. No difference with the fan. Still didnt come on. That makes sense that there are 2 sensors. But I cant find the other one if its there. Here is a photo of the engine wiring from a shop manual showing only one sensor. I believe manual trans cars have one fan and automatics have two. Wiring and sensors could be all different.
Rich

 

[Greg Corcoran]

Rich,
The ECT sensor on my '95 MTX is further toward the firewall and a bit lower than the sender for the gauge. The single post gauge sender is the one labeled in the diagram. If memory serves, the connector is gray, and it has 2 wires. In the diagram you attached I think it is the wires to the sensor that is not labeled down and to the right on the diagram. It is somewhere in that area anyway.
The CELO (Cold Engine Lock Out) switch is also in that area, but closer to the firewall in the hose/pipe to the heater core if you have EATC. That also has 2 wires I think, So maybe if you are on good terms with your local NAPA, O'Riellys, etc ask them to order the ECT for you so you know when you are looking at the correct sensor.
Greg

 

[Irish Pride]

Thermostat housing and rear sensor.

-Chad

 

[Greg Corcoran]

Thermostat housing and rear sensor.

-Chad

View attachment 87591

Thanks Chad!
Rich, So if I call the ECT in this picture is at 4 o'clock, then the single post sender for the gauge is at 7 o/clock. This should help you find it.

 

[Rich G]

Thanks Chad!
Rich, So if I call the ECT in this picture is at 4 o'clock, then the single post sender for the gauge is at 7 o/clock. This should help you find it.

HA! I think I can find it now. Thanks for that diagram. That is a huge help. I cant believe the shop book didn't mark it.
Won't get to it till the weekend but I will let you know how it works out.
Rich

 

[Rich G]

Update,
I had to put the car repair on hold for a bit, but finally got to it.
I disconnected the sensor wire while the engine was running and the fan came on.
I got a sensor from the auto parts store, changed it, and the fan kicked on just like it supposed to.
That saved me a lot of agravation of changing the relay box when it wasnt the correct bad part.
Many thanks to everyone for all the help and pictures.
Rich