I have a 1970 f600 dump. It has the electric Eaton 2speed rear end. It’s been stuck in low since I bought it. I replaced the electric motor but it didn’t fix the issue. The motor was definitely bad.

I don’t have any power on any of the wires at the switch on the shifter. There’s a green, black and red. Should I have 12 volts on the green wire and then the switch puts power to either the red or the black depending on if it’s in high or low? I looked up wiring diagrams for the 2 speed and there’s a speedo adapter in line with the black wire. Where is the speedo adapter? Could that be my problem? It’s an old farm truck so I don’t particularly care if the speedo adapter is working, so could I just run 12 volts off the ignition on the green wire and it should work? Should I replace the switch as well? I just want to get the two speed working so I can go over 40mph. Any advice in troubleshooting the problem would be great. Thanks.

 

On the right side kick panel is the main fuse board, the breaker for the 2 spd shifter is there, it could be blown, and the shift lever switch could also be bad.

 

Ok so why not with a jumper wire jump the switch on the shift to battery does it work?
You should hear it. If not run a long jumper wire to each wire on the axle; it should do
something, if not and with a new motor I think it needs that board with points inside the
housing or cleaning ; Napa has those. First take the whole thing off and bench test it and prob that point board with a battery charger will do. Prob one point, motor should run one way and
prob the other point motor should run backwards now prob the wires coming in and if nothing the 'terminal point board' is sick or done. I should have first said to disconect wires at the axle and with test light ign key on light should light both button up or down, if so thats good then its the points in the motor housing. Hard for me cause I'm
a hands on, not story writer, But here goes I'll try;; button down motor spins; the lead screw comes a stop "opening the low points" which now contacts the button up
which now the high = point power is dead until you pull button up points close- motor
reverses motor lead screw hits stop and the high/ motor power goes dead and the points goes back to low "no power until you pop the button to low". so simple. And the speedometer is a solenoid & gets powered when in low side button down. Made
simple the point board: think of a sea saw; one side, power, other dead, other side alive best I can help you sam Just did one this last summer The board >Napa
control'd by the lead screw stop