11
If problem is not found, check the cable on the motor for continuity. BE CAREFUL
NOT TO SHORT THE SOCKET WITH OHMETER PROBE. (Battery voltage normally
exists on the black and white terminals) Check the orange wire in the cable. With plug
unplugged, check with an ohmmeter for continuity from the motor terminal strip to the socket
hole corresponding to orange. (See plug/socket assignment above) If you get continuity in
the motor cable and the socket appears satisfactory, the trouble is isolated to the control cable
and plug.
To check the control cable on boat for continuity of the orange wire, place one probe of the
voltmeter on the prong of the plug. Extend the length of the other probe, if necessary, with a
piece of wire to the screw on the control console terminal strip corresponding to orange.
Other Control Circuits
You can check the other two-contactor control circuit following procedures similar to
those above. Just trace the applicable colored wire from the contactor coil through to the
terminal strip in the console as we did above. If necessary, make continuity checks on the
motor cable to the applicable socket hole and then similar checks of the control cable on boat.
Shorts in the Control Cable
Shorts across wires in motor cable or control cable can cause various unexplained
malfunctions of the system. To check for shorts in the control cable and motor cable unplug
the control cable connector. Remove cable wires from the motor terminal strip and check for
shorts between wires in the motor cable with an ohmmeter. There should be no shorts.
Remove control cable wires from terminal strip at console and check for shorts in control
cable. If shorted, applicable cable must be replaced.
The PMC (Pulse Modulated Control) and associated circuits
If the contactors are operating normally and the motor still will not function, suspect
an open primary terminal inside the cowl, the PMC, the three control wires to the PMC --
blue, brown and red, or the potentiometer.
First, check for a shorted plugging diode. (See function of plugging diode at end of
"How it Works" above) If this is the problem, the PMC output is shorted inside the PMC. If
left on for any length of time, the PMC will get hot and additional damage will occur. The
PMC will work without the plugging diode if additional damage has not occurred. Removing
the A2 PMC to A2 motor wire (W264) removes the plugging diode from the circuit. If a
shorted plugging diode is suspected, remove the A2 wire. If motor then runs, it means the
diode is shorted. Without the plugging diode, reversing will be harsh and even dangerous on
tiller models. PMC should be replaced. If plugging diode is not the problem, proceed to next
step.
