Still having problems with my 90 SC

ddwood55

Registered User
A few weeks back I asked for some help on the A/C, antilock brake light and radio.

Well I still need help with the A/C and I also I have a new problem.

First the A/C. Clutch will not engage. In my first post I stated that I had the low pressure switch jumpered out. I have power there. But I don't have power at the compressor plug.

edspringer posted a reply stating that I need to check the gray wire with a white strip at the IRCM located behind the passanger headlight.

Well I found the IRCM but no gray wire with white stripe. I can go out and write down and post all the wire colors if needed.

The other morning, the blower motor just quit working (figures we were getting freezing rain, sleet and snow at the time!). I've checked the fuses. #11 a 30 amp fuse, it was good. Also checked J (under hood) blower motor/ignition switch, it was good also. I have no power to the blower switch. What do I need to check next?

thanks, Delos
 
I found this online, Carquest temperature control, Tech Tips

Testing Ford's IRCM/CCRM for no clutch operation

Pin 21 Battery voltage, When driver sclects A/C, power flows through the pressure switch to both the PCM and the IRCM If there is low or no voltage, check fuse, switch and pressure switch(es).

I have battery voltage 13.7 volts on this wire BK/O


Pin 22 6 to 7 volts, when PCM recieves an A/C request, it sends a trigger voltage to the A/C relay for clutch operation. If ther is no voltage, then the PCM has detected a problem with engine operation and will not allow the clutch to engage. Check the PCM for codes and other engine performance concerns.

On this wire, also a BK/O I also have 13.7 volts. I'm getting tired so I haven't pulled codes. I'll try and get this done tomorrow afternoon.

Pin 23 Battery Voltage. With the A/C relay triggered, voltage flows from this terminal to the clutch. If the clutch does not engage check the clutch air gap, coil resistance and ground circuit. If the low or no voltage, replace the IRCM/CCRM

I have 13.7 volts on this wire also. It's a BR/Y wire.

Now I'm going by a 1991 wiring diagram, it's all I have. I have a complete set of wiring diagrams for the 91 model year that covers all ford cars.

Going by the terminal (Pin) numbers that the carquest test tips gave me for the IRCM and the color codes off the wiring diagram match the colors for the wires on each pin number I checked so assume it's correct.

So why do I have 13.7 volts on pin 22 when that is suspose to be the signal voltage 6 to 7 volts from the PCM. Do I have a PCM problem? Is it a bad IRCM? or both?

Oh one other thing I checked. My wiring diagram shows that Pin 19 is the blower motor feed. I figured this wire should have battery voltage, but it was only showing 8 volts. It's a BR/0 wire.

Any ideas on what I should do next?
 
Pin 23 Battery Voltage. With the A/C relay triggered, voltage flows from this terminal to the clutch. If the clutch does not engage check the clutch air gap, coil resistance and ground circuit. If the low or no voltage, replace the IRCM/CCRM

I have 13.7 volts on this wire also. It's a BR/Y wire.
If this wire is the same at the compressor itself, then you have power all the way up to the clutch coil. You should be able to test for power at that connector. If thats the case, you have a bad clutch coil.
 
If this wire is the same at the compressor itself, then you have power all the way up to the clutch coil. You should be able to test for power at that connector. If thats the case, you have a bad clutch coil.


That's just it. I don't have power at the connector at the compressor. It's dead, no voltage at all.

Delos
 
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