[Mgs] Overdrive does not work when it is hot. Checking for an open circuit

[Ed Woods]

List,

Lacking an ammeter, an electrical test that I used was to put a 12V bulb in 
series with the overdrive electrics. Did this under the hood, a.k.a. bonnet, 
where the connector to the o/d is located. With the ignition on and the 
gearbox in 3rd or 4th and, of course, the overdrive switch "on", the light 
will illuminate dimly if there's continuity to ground through  the various 
wires, isolator switch, and solenoid.

Ed Woods