1920 electrical problem

[AlbionWood]

View attachment 685951 17 is the fuse box.

Yeah... I have spent hours poring over that diagram, and the one for the 2120 that shows the color codes. I find them confusing and largely unhelpful. There are several unlabeled objects, and symbols that I don't understand, and wires that change color, and some of the sender units don't seem to be in a circuit - there's only one wire shown and it goes directly to the instrument panel. I guess they are powered from the panel? But where does the panel power originate? Clearly I studied the wrong kind of engineering.

 

[AlbionWood]

My last rodent (mouse) encounter yielded a batch of chewed wires in my wiring harness that feeds the instrument panel. Very tedious job mending all of those wires. Hope your mouse was not as hungry as mine.

Man, that would be a tedious job. I'm likely headed down the same road, if it's not just the alternator causing all the problem. Oddly, the mice do not appear to have chewed on any of the wiring. Perhaps it's the coating of hydraulic fluid mixed with dust that made them unpalatable.

 

[kirkawilson]

I got so tired of chasing electrical problems on my NH1920 that I installed a push button start switch on my dash and wired it between the starter battery post and the solenoid post to completely bypass the wiring harness including all electrical safeties. It does the same thing as the screwdriver shunt at the starter. You still must turn on the switch to open the fuel shut off solenoid but the push button is 'live' all the time and can be a safety hazard in the wrong hands. After a about a year of using the push button successfully, I finally discovered the source of my starting problems as a bad neutral start relay.

 

[AlbionWood]

Finally coming back with what I hope is the end of the story. I never did find anything obvious, but took apart as many connections as I could find, cleaned the connectors, and then washed off the whole engine. Let it dry out and when I started it up, looky there, the gauges are working again!
Man, it's nice to have a working fuel gauge... on a diesel engine... bleeding those lines is a nuisance.

Oh, and I did get a battery load tester. It's fine.