Re: Continuing on the Overdrive

Posted by HH56 On 2009/8/26 11:30:24

The EC has a separate fuse so other than also getting ground at the governor, it is totally independent.

With machine gunning, it's possible the #3 wire is bad or also possible there is a problem in relay. Since solenoid worked properly with 3 & 4 connected on bench, that tends to lead that way. The 20 amp fuse wouldn't have caused it--just blown when it was doing it.

There was a modification in late 40's to add a safety switch to open the hot wire when in reverse. It may have also been done to your car so that would be a good thing to check.

Terminal 1 of the relay should have power at all times if no switch was added and at all times except when in reverse if it was. Using your test light with one side to ground, check that terminal and see if power present--If later switch used, it was operated by reverse lever so also wiggle the gearshift when checking other gears & make sure not mis-adjusted. If that is OK, then if the governor is grounded you should also have a light at terminal 4 and 3. If so, relay is good and would try the external wires. Just use some wire approx the size of the ones in loom and make sure if solenoid not mounted, that is has a good solid ground of at least same size wire bolted to mounting hole and frame ground.

If power is at 1 but not 3 & 4 with governor grounded, then need to check the wiring and the lockout, & kickdown switches coming into terminal 5.

An added note: I don't know the particulars of your loom but just remembered there was also a bulletin in later years about the overdrive harness. The black connectors where a short loom containing the 6 wires from governor and solenoid joined the main loom having poor connections was the issue. If your loom is 2 piece constructed the same way with those connectors, might be worth a look.