Fisher MM II Electrical Troubleshoot Joystick? Harness?
I just did my fluid change a few days ago ( Fisher MM II HD on 2004 f250 SD ) and when I went to cycle the plow to remove air and top off the reservoir I had an unresponsive joystick control with no red indicator light.
Everything was working normally last season.
I have been reading up here in the meantime and have also changed my relay and changed the fuses near the isolation box with no change so I have now started electrical testing to isolate the issue. Looking for some advice to help me wrap my head around this so I can correctly diagnose what I need.
No voltage readings on the grill connections for the plow power and controls. But my plow lights are working normally. Do I need the circuit to be connected to get a reading?
Changed relay and fuses. Relay has power on one large post. the other large posts and 2 small posts I assume will only get a reading when the joystick is operated.
Cleaned and checked terminals and grounds on the truck.
Jumped the battery to the plow motor and the motor is operating.
Checked for power to the joystick. I have 13V power from the switched power source wire but I am not getting any reading on the 6 pin connector with a multi meter. What voltage should I have from the 6 pin connector?
I don't have another joystick to test with but for now I am assuming the joystick is OK and not lighting up because I cant get a power reading on the 6 pin. Is this a incorrect assumption?
What else could I be overlooking besides a fault in the harness?
Does the circuit need to be closed with all the connections together to get the joystick indicator to light up? Any reason to think it is a problem with the plow motor ground / power connection.
Thanks in advance. Any advice is appreciated. I will be keeping an eye on this so I will gladly answer any questions or perform further tests. It seems strange to me that a wiring harness would go bad between seasons but I am sure stranger things have happened.