UPDATE:
Lost job after 37 years
Had to put a new engine in the truck----190,000 pasture miles (it was due as oil pressure dropped to zero at idle and had been knocking for a couple of years now)
Started new job and have had little time to mess with it.
Just picked up the truck today after getting engine installed and put it up on a rack.
Removed the actuator and fired the truck up---put in 4-low and and let it idle.
Front driveshaft is turning and it is positive, not just floating with the t/c.
Floor indicator not coming on and actuator not engaged (plugged in hanging)
Insert an extension bar into the front end and the differential engages just fine.
Unplug actuator switch and plug a loose switch to the harness
Actuator starts dancing at the end of it's harness like it is trying to engage.
Plug harness back to t/c and play with wiring over the top of the t/c and the actuator starts dancing again.
This kind of tells me that there is a bad wire somewhere in the harness.
Now, I have looked for a STANDARD wiring diagram for this truck and cannot locate one anywhere.
Manual 5spd with a NP241C t/c
The only electrical connections on this t/c are for:
VSS
Differential actuator
Does anyone have an electrical diagram that will show the wiring of a BASE
5-spd 4x4----no dash switches, no dash indicators--the only indicator is a lamp on the floor shifter that lights when it is placed in either of the 4x4 positions.
This lamp has stopped working as well---was working earlier in the summer.
The only diagrams that I can find are for the trucks with the buttons on the dash and automatic transmissions---my truck has neither.
If this thing has relays or modules, I have no idea where they may be located. Still kind of anxious to get the 4x4 working, especially now that I know it is not mechanical.
The good news is that my truck no longer rattles at a light and the oil pressure is staying at 40+ all the time.
