International Loadstar question

[dairyman]

Does anyone have a wiring diagram for a 1975 International 1600 Loadstar truck? The two speed axle stopped shifting and I think that the problem is with the electrical relay in the dash because I dont hear it clicking anymore when I try to shift the axle. Any ideas what could be causing this? Also are parts still available or do I need to get the parts from a junkyard?
thanks for the help
David Carlson

 

[the tractor vet]

Check the points in the two speed motor cover on the back axle and check there also for juice.

 

[Allan in NE]

Boy, I don't think so Dave.

That "clicking" in the dash area you hear is the solenoid changing to re-ratio the speedometer.

Problem "usually" lies back at that change switching box at the axle. Take your test light and see if you have juice at the high or low terminals there.

If not, check the manual switch and fuse.

Repair kits can be had at any IH, Chevrolet or Ford dealer.

Allan

 

[Anonymous-0]

that switch is just a two position switch and there is no relay you have a bad shift motor or broken spring and it all on the rear
end most of the time it's a easy fix check if you have electric power to the rear

 

[Bob]

If the system has power, and the switch on the shift "stalk" is working, you should hear the speedo ratio change solenoid under the dash "snapping" even if the rear axle unit IS NOT shifting. Typically, a circuit breaker is used, rather than a fuse, so it resets.

Check all your breakers, then probe the connector at the switch. The center terminal should be "HOT" as long as the key is "ON", and power should alternate between the other two terminals, as the switch is cycled up or down. If you have power that far, and the solenoid under the dash is working, check out the wiring to the back, and finally the electric shifter unit. NAPA will have the motor, the leadscrew, and the limit switch, as needed.

If it turns out the motor has failed, one cause is the sort of "bellows seal" between the shift unit and the rear axle. If torn, heavy gear oil will get in the shift unit, instead of the small amount of light engine oil that's supposed to be in there.

 

[dairyman]

Thanks for all the help everyone. Hopefully now I can get this truck back up and running the way it's supposed to.

Dave Carlson