You may not want to hear this. The CCRM is only really a PIA to trouble shoot to the "parts changers" of the world that are not willing to run and post the several trouble shooting steps needed to determine exactly what is really wrong. Most of the "parts changers" out there are mainly interested in the silver bullet that will solve their problem. In and out as quickly as possible with no work required.
If your goal is to correctly trouble shoot this problem then there is some information that is needed as well as some key tests..
Do you have an ODB2 scanner? It might make very short work of this problem to know:
- What the PCM "thinks" is the engine coolant temperature is (ECT)
- What fan speed is the PCM calling for?
ForScan ODB2 scanner w ELM327 USB
While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...
www.stangnet.com
Once this is known is actually very easy to test IF the CCRM is receiving the correct commands. Further if the CCRM is producing the correct output.
For the first test I would like to know IF there is key on, AC on, power at the low pressure cycling switch. Best to use a test light that will "load" the circuit.
IF no power at the low pressure switch, Then look for a blown fuse or a problem in the AC mode control switch.
If power at the low pressure switch, then more tests are needed.
NOTE: should you wish to try changing out the CCRM, please note that not all CCRM's are the same. There are differences between the model years as well as the engine type. It's very important to get the correct CCRM for the application. I have helped more than one person with a bad CCRM who replaced it with the wrong CCRM. When it didn't solve the problem they concluded that their problem wasn't the CCRM.
