I wanted to jump in with both feet on this, but I’ve hit a wall.
This is the mosfet and its heat sink. With no visible damage to any of the components, I started checking them one at a time, but I made a major error.
I got in touch with a local electronics guru, who informed me that my list of failed components was, well, inconclusive at best. Some of you pointed out that things like capacitors and transistors cannot be tested in-circuit. Apparently that’s true for the other components as well.
To confirm this, I started by de-soldering one of the bad resistors and testing it by itself. It was good after all! Something else in the circuit was throwing me off, big time. So all of my component checks (except for maybe the coil relays) would have to be done all over again. That means de-soldering each one just to see if it’s still good.
Needless to say, it’s a bit more work than I bargained for.
Feeling a mix of reluctance and dutifulness, I decided to start with the MOSFET. After some finagling with my soldering iron (a cheap little 30w in need of an upgrade), I freed the MOSFET along with its heat sink. And wouldn’t ya know, it passed the same test that it “failed” while still connected to the board.
But that was just a preliminary diode check between 2 of the 3 terminals. I couldn’t give it a clean bill of health without performing a different kind of test. But first, I needed specs.
And that’s where I hit a wall. I could not find any data sheets in reference to the number printed on the MOSFET. And neither could my contact. It appears to be obselete now, and I can’t find CCRM specs to seek out an equivalent.
That means two things: I can’t test this one, and I couldn’t get a replacement if this one tested bad anyway.
Welp, looks like I’m getting a new (reman) CCRM.
At least I learned a few things by opening this up. Maybe sometime in the future I’ll crack into a PCM or ABS module, and actually be able to fix it. Or maybe I’ll just recognize my limits sooner and waste no time in getting a replacment. Thanks again to everyone for your comments and support!