Ωhm

Let me know if you can or cannot open this. _mj1988electricalmanual_1.pdf

Try and get that Red Brick Tester (RBT) online. Both TCU B+'s & GND seem good. Check continuity between C234_C4 and D2_15 (serial data line).

Never doubt a "good eye".

You've seen this before? That's interesting and well worth knowing.

With AC selected and when the compressor clutch engages, does the Cooling Fan also engage?

Since you have a Radiator Temperature Switch (RTS) connector that goes no where, is the Cooling Fan ON with the KEY ON? Is vehicle equipped with AC?

Color codes seem to be correct for that connector. YEL & GRY w/TR Do you have a factory Cooling Fan Relay?

Good VID. I always thought cross strapping had two (2) purposes. 1.Prevents LEFT/RIGHT drift. 2.More strap (longer) allows for more stretch in the strap. Short straps put a lot of tension in one short spot. What a disaster using cross strapping and one strap is losed. Is his grille upside down?

Two (2) pins for 12vdc. C234_D14; B+ (Hot at all times) C234_D16; IGN SW (Hot with KEY ON)

Since you have NO communication with TCU and NO shifting solenoids, do you have continuity between D2_7 and battery negative terminal (B-)? Looking for a completed ground circuit back to the battery.

Listening to Automotive News on the radio lately and lots of talk about this. Let the smack talking begin

That's one thing a REM doesn't do, is tell you that you have a mechanical problem. Glad you figured it out.

You need to know where the CAM timing is at. When CRANK/CAM timing marks are aligned, what position are the valves at for CYL#1? I'm not even sure if the CRANK/CAM timing marks are set for CYL#1.

Maybe I can answer my own question. Vehicle was built in Venezuela.

Nice job. Was looking at all engines. 1?. 8YFFJ26VXNV071840 Shown as MY92 with 4.0 HO but VIN8=V

Is it possible that the Radiator Temperature Switch being used has inverse logic, of say an MJ Radiator Temperature Switch? In other words, is the Switch closed when COLD and opens when HOT. As for switching B+ or GND to/from the FAN, that one works either way.

Do you cycle the KEY ON then OFF? May have to wake up the Chime Module.

Under Browse/Forum there's a MJ TECH: DIY project section. Here's example: https://comancheclub.com/topic/45839-mj-height-sensing-brake-proportioning-valve-adjustment-procedure/

Your missing the rod for the rear brakes porportioning valve. Its held up with a tyrap. Welcome to the CC forum. Add your VIN to the registry. Also, LOG-IN. Upper right hand of screen. Click on Username. Click on Account Settings. Find and click on Signature. Add vehicle information here (YR, ENG, TRANS, etc, etc) and save. This helps everyone. This information will be available every time you post.

Voltmeters can fool you, they don't tax (current flow) the circuit. Testlight requires current flow to light the light. Example being a 10 stranded wire with 9 wires broke, voltmeter will show 12vdc but testlight will glow dimly.

Check it using a Testlight.

It's a title given to a Engine Control Unit (ECU).

STFT. Numbers less than 128 take fuel away by cutting back on INJ PW time. In other words the O2S is seeing RICH. Check O2S heater circuit. KEY OFF. Check continuity between D1_3 and D2_9. Looking for ≈6 ohms. Wiggle wires/lightly, very lightly tap O2S.

RADIO FUSE (15A).