1990 B2600i MaxiCab with no spark

ByeCustoms

Hey! I am having some serious trouble with my 1990 Mazda B2600i MaxiCab 4x4.

So the backstory: I was driving to school and it ran perfect, like it was new! So I parked at school and when I was reversing out of the parking lot to go home, it died! Just like you turned the ignition off.
So I checked for spark, and there was no spark. Plugs look very dry as well so I assume it has no injector pulse either. Fuel pump works as it should.
I troubleshooted what I could with the knowledge I have, and found that there is no spark even from ignition coil.
What has been done so far: New ignition coil, new igniter, new ICM in distributor, new rotor, ECM has been checked over, Main Relay has been checked as well as all fuses and voltage at ignition coil has been checked. (12,5V with ign. on, 10,5V while cranking) Heard that coil can be checked with LED test light as well, on the white pigtail by the coil, while cranking the LED light stays lit, no flashing. Whatever that means 🤷‍♂️
I have probably forgotten something, but oh well.
I have tried looking at wiring diagrams but I can't really make sense of them...

I have been scrolling trough all forum posts and everything I can find, but nothing seems to help..
I really want to get this truck fixed now as it is my only form of transportation and it has been sitting for about 4 months...
Thanks in advance for any and all help / David

Axel-Breaker-Earl

There is a known issue where the electrical portion of the ignition switch may not power the coil when trying to crank /start the engine. Try to see if you can run a separate (+)12v from the battery to the (+) terminal of the coil, then crank the engine over. If the engine starts, then install a new ignition switch (electrical portion of it).

Red91EFI

Axel-Breaker-Earl .

Do you recommend a brand name for the ignition switch. I saw a video on youtube and they were using a Duralast ignition switch.

ByeCustoms

Axel-Breaker-Earl How would I do that? The plug isn't big enough to squeeze another wire in there. By the way, I have checked the 2-pin plug to the coil with a voltmeter and it has 12,5V with ign. on and 10,5V while cranking, shouldn't that indicate that the ignition switch is good?

ByeCustoms

If anyone know if the numbers on the ICM/Crank Angle Sensor matter, please let me know. I replaced mine with the numbers J925 0312 with a different one with numbers J925 XXXX (can't remember the last four now)
I'm pretty convinced it's the ICM/Crank Angle Sensor that's messing it up, since I get no pulsating signal at the Tach-pigtail at the coil. So if I'm correct the ignition coil is not getting the signal to fire.

ByeCustoms

Where is the "Main Relay" located? The one illustraded in the wiring diagram, is that the metal relay marked "G607 Denso" or is it located somewhere else? The "G607" wires in my truck don't match the ones in the diagram so I suspect the "Main Relay" being located somewhere else. The wires on diagram are: 2 Blue/White wires, 1 Black/Yellow and 1 Blue/Black. At the "G607" connector on my truck they are Blue/White, Blue/Black/ Blue/Red and Yellow.

ByeCustoms

ByeCustoms Reason for asking this question: On the B/Y wire at Crank Angle Sensor I have 0V, but it should be 12V if I'm correct, at least it should have power. Tracing that wire back to connector between INJ. harness and EM. harness I get 1,1V on B/Y wire at the EM side and 5V at 30A INJ. fuse, with fuse removed. Should be 12V at fuse, right?
Not really sure how to continue from here, I can't quite understand the wiring diagram after the fuses and how to trace it.