Re: 1939 Six Overdive

Posted by HH56 On 2017/2/1 21:18:11

For troubleshooting, there should be two wires on the ignition coil primary terminal. One goes to the distributor and the other goes to the OD kickdown sw. Remove the wire going to the kickdown switch and leave the one going to the dist connected. That will totally remove any connection comng from the OD. If the engine still stalls the OD and its circuitry is not the problem however, if the engine runs normally you need to check the OD switches and electrical components for operation and the wiring for bad insulation and possible shorts to ground.

The OD will still engage with the wire disconnected but it will not kick down smoothly (or at all) when passing or when a forced kickdown is requested. Without the wire the ign cutout can not cause the engine to lose torque momentarily and let the OD components disengage. If you find the stalling problem is due to the OD best to repair it or else leave the wire disconnected and lock out the OD until you can fix the problem.

There is an early and late version of the 39 OD wiring. The late version has an extra switch operated by the reverse shift lever at the base of the steering column. If you have that switch, make sure it is only being activated when in reverse.