These are the “1 Piece Plug” and Universal Wiring Harnesses. The 1 Piece Plug made its debut with the MDII Mount. The MDII made it necessary to unplug EACH plow light, the 3 individual Coil wires, and the Motor Harness to remove the complete plow assembly. Meyer came out with the 1 Piece Plug. The very first consisted of a short truckside harness that the individual wires could be plugged into, and a plowside harness that would connect to the E-47H, E-57H, or the E-60H.
Once it was clear moving forward that the whole plow assembly would be removed as a unit, the 22261 Truckside Harness evolved into the 22610 truckside harness. The Touchpad Controller was standard, so the harness had a plug for the Touchpad in the cab.
There was also the debut of the E-58H around the same time, so a hydraulic side harness (22604) for that came out.
Next came the Pistol Grip 22690 Controller. Since the 22691 Universal Harness was already in use on the Xpress Plows, it made sense to use the same harness, in fact, it became the Universal Harness. So the plug in the cab changed to the Universal Pistol Grip plug. This way it would be used with the E-58H, the Xpress Plows, and even the V Plows.
Naturally now that the truckside had a round plug, the various plowside harnesses came out as well.
Finally! Now we are up to what is current!
Now, here are the pin outs for all of the above harnesses to aid in wiring and troubleshooting your Meyer plow wiring.
ALL of the “Rectangular” plugs:
The Universal Harnesses:
and finally, the plug in the cab: