Strange A/C Issue

[Sylentnite]

The SHO has another temp sensor on the back of the block (drivers side) that activates the fan(s) when it reaches an elevated temp. ten it shuts off the fans when the temp comes down

Turning on the a/c will activate the Fan(s) regardless of engine temp.
There is a secondary sensor at the back of the engine (drivers side) that activates the fans (as needed) when the a/c is not on and the engine temp reaches an upper degree.

Turning on the a/c will automatically activate the fans (full time).
It is my understanding that with the a/c on and the fans running that when the SHO reaches a certain speed 50 mph (or so) the ECU will shut down the fans until the SHO comes down in speed.

If your fans are coming on (when it reaches) higher temps then (at least) the fan motor is working. This points to a probable fault at the CCRM.


I hope this helps.

I ran 12 volts from the CCRM connector to the clutch coil and the clutch engaged. I checked the voltage with the car running and AC on from pin 23 &16 which is the output going to the coil going by the above diagram and I have no voltage. Also the input pin(21) from the EATC is only reading 1.7 volts. Is that right, or should it be 12? If 1.7 is correct im thinking it's the CCRM, if not im thinking possibly the EATC.

 

[Sylentnite]

Update:
I ran 12 volts to pin 21(EATC output to CCRM), the AC clutch kicked in, and fans came on. My question is, before I buy a EATC, are there any other switches/sensors in between the EATC and CCRM that would cause 12 volts not to reach the CCRM to activate the AC clutch relay? I had the cycling switch on the dryer bypassed.

 

[FastCAD]

I have 93 Atx, I redid the entire AC(Compressor,dryer,etc) system in 2018. This whole winter my A/C hasn't been working, I've needed it to clear my windows occasionally and noticed the clutch wasn't kicking in. Even on a 60-65 day the A/C clutch wouldn't engage. Yesterday temp here was about 70-75, and tried the A/C and it worked fine(Ice cold) the entire day. I did try jumping the Dryer switch during the winter to see if the clutch would engage, and it wouldn't. Is there a temp sensor or something that is causing the A/C clutch not to engage in cooler weather?

The fans do work, when the car gets up to temp, I hear them kick on to cool the car off, they just don't kick on when I press the AC button.
If I short the cycle switch on the dryer and it still doesn't kick on that would eliminate it being the cycle switch correct?
What pin is it from the CCRM that goes to the compressor to verify the coil is getting power?

The fans do work, when the car gets up to temp, I hear them kick on to cool the car off, they just don't kick on when I press the AC button.
If I short the cycle switch on the dryer and it still doesn't kick on that would eliminate it being the cycle switch correct?
What pin is it from the CCRM that goes to the compressor to verify the coil is getting power?

I ran 12 volts from the CCRM connector to the clutch coil and the clutch engaged. I checked the voltage with the car running and AC on from pin 23 &16 which is the output going to the coil going by the above diagram and I have no voltage. Also the input pin(21) from the EATC is only reading 1.7 volts. Is that right, or should it be 12? If 1.7 is correct im thinking it's the CCRM, if not im thinking possibly the EATC.

"Four Seasons Auxiliary Fan Control Unit" part#5546-09055975 ('93 SHO 3.2L). https://www.partsgeek.com/catalog/1993/ford/taurus/cooling_system/auxiliary_fan_control_unit.html
You can search other vendors to maybe get a better $$$ but be careful.
The #5546 is the mfg. #.

 

[NoSlo]

You likely have a faulty pressure switch if you have indeed checked the pressure at the dryer/accumulator and it is >50 PSI. I replaced one that tested OK with the multimeter but apparently didn't carry enough current to turn on the CCRM.

Also:

One could monitor the pressure switch connector for +12V (pink wire side) to see if the EATC is engaging AC.

 

[Sylentnite]

You likely have a faulty pressure switch if you have indeed checked the pressure at the dryer/accumulator and it is >50 PSI. I replaced one that tested OK with the multimeter but apparently didn't carry enough current to turn on the CCRM.


Also:

I've always hated when I've searched issues on forums and the originator doesn't post what they did to fix their problem. With that said mine is fixed, it indeed was the EATC, I took it apart and there was a solder point on the circuit board that had come a loose. I found someone else had this issue on a Lincoln. I soldered it back as best as I could and I now have cold air. Thanks for the help.

 

[tompumped]

I agree.
Is there a pic of this solder point?