Overdrive wiring issue

Posted by Jim Kavanagh On 2019/4/2 0:05:18

I have an R9 on my 41 120. Both Overdrive and Electromatic Clutch. Both the OD and EC have always worked.
I recently changed out the OD solenoid. I did mark the wiring, but it is not impossible that I messed up.

Once changed out, the new solenoid operated only a few times and then would no longer engage. Afterward, I could not engage the solenoid by grounding the OD wire at the governor. I then replaced the solenoid with the original one.

When changing the solenoid, I noted that the EC wire on the governor was quite loose, so I screwed in the screw to tighten the wire. When done, as soon as I pushed in the OD dash lever, I could hear the solenoid click and engage (this is while ildeling, or even with the engine off, but the key on) and the indicator light on the dash would light.

At this point, the dash knob was completing the circuit, so the governor switch had to be grounded. Obviously, I did not reverse or move the car with the solenoid so engaged.

After puzzling for a day, I pulled the EC terminal screw at the governor (that I had screwed in to tightened) and noted it was very long - probably longer than an inch. I think that tightening it down actually grounded the unit due to the length. I replaced it with a shorter one, and now I get no engagement when I push the OD dash knob in (and the indicator light stays out), so, at stand still, the solenoid is not engaged. Unfortunatey, I also do not get any engagement after I hit 18 MPH (and no indicator light), or at any speed.

The other condition I noted with the long screw completely turned in was that the middle contact on the EC relay unit would engage as soon as I engaged the battery with everything else off - including the key. I have a kill switch and tested this several times. I could do nothing, except remove the EC unit fuse, to stop this from happening as soon as the battery power was provided.

Now that the shorter screw is in the governor, This contact no longer energizes when I provide battery power.

The EC unit does work fine, so I feel that the governor is working, although the solenoid does not energize under operation. It did on my bench before I re-installed it.

I tested the continuity of the wiring between the OD relay and the solenoid. Contacts 2 and 3 seem to be wired as shown in the OD training manual, however, the 4 and 6 terminals may be reversed. I know the wiring is correct at the relay, and believe it is correct at the solenoid, that is it is as it has always been, but again, I could be wrong.

What would be the effect if these two wires are switched? Can I reverse these without risking damage to the unit?
Just because grounding the governor earlier and having that grounding result in the solenoid pull-in and hold-in circuits working, it makes me think that the issue of not now engaging at speed is related to the governor. But I am not sure if that logic holds up.

This is obviously an electric issue, any other thoughts as to the cause of the current situation?