Update: ok, so where to start. I guess with the gauges. Since the bulbs werent making good connections I had an idea, at least for a test. I took a couple of pieces of wire just to use as "Brushes" for the bulbs contacts...
It worked pretty well and we actually ended up with some dash lights...
It was great to see those finally, however, it was still intermittent. As soon as I started to pick up the dash the lights went out. Went round and round with them and at the end of the day, the plug is not making good contact with the pins either.
I can test the wires all day long and they are good and the circuit performs as expected. But not the connection to the board, or the board to the lights. Not sure how easy or hard it will be to get into those plugs. After that discovery I set it aside. Still seriously considering using LED indicator lights on the original dash, and connecting directly to the wires. Will do some more thinking on it.
So, more dash related stuff. I reinstalled the thermostat, and tested the coolant gauge on the dash. It actually functioned well, getting up to halfway and holding there. And going back down as the engine cooled. There's a little nub of needle left, not sure if you can see it very well in this pic.
Fuel gauge...I originally thought the fuel low sensor worked because the light came on and the fuel was low, but after I filled the tank halfway with diesel, it still didn't go out. The fuel gauge is also not working (or the sender isnt) because the gauge never moved from half. I think the sender unit as a whole is bad...when i went through the gauge test procedure, the result was as expected...but the sender unit test failed.
From there I pretty much tested every circuit front to back. The oil pressure sensor, I checked while not running, then while running, etc. Through all the circuits. Everything is wired up in the harnesses to the dash/key/lights switch/Fuse panel as it should be now. So on to the headlights...
This is what we were starting with. (as a side note I dislike battery retaining bars that are on the same side as the terminals. so I flipped the battery, cleaned off the frame and main ground lead, and moved the lead to the left side. ...back to the headlights...) The wiring diagram shows 5 wires up front. Secondary circuit ground (not frame ground), ground for headlights, battery low wire, low beam, and high beam.
I was figuring out my approach because I wanted to leave the original wire colors showing if at all possible. So I started de-looming the wires...and this...the headlight grounds were just a "V'd" wire taped into the harness going nowhere. bizarre.
Anyway, glad I de-loomed it. Got the lows and highs wired up and....
With that done, everything Electrical from the firewall forward has been tested (except the glow plugs) so I put harness 1 and 2 back together. I still need to make them pretty, I'm just not sure how they are routed from the factory. Especially the harness going around the radiator. I'll finish the loom at the firewall when those two harnesses are ready to go together. And the blue and white plug in the middle of the right harness is the coolant reservoir sensor...but since there is no reservoir...
And the left side... That blue and white plug is the "Fusible link". Glad this half is done...
That's it for the evening...Have a great week ahead everyone...
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