hi folks ive got a 48 linc.that it trys to go into od the lite on the dash lites up when you let off the accel. and as you re accel the lite goes out its got a new wiring harness the relay is good the lock out switch is good the gov. is good ive evan bypassed it and it still wont stay in.ive hade the trans out twice and on the bench it goes in just fine every time the trans work perfect otherwise .ive taken apart the od twice it it all seems good to me. ive rebulit hundreds or transmissions but havent had a problem like this before. the cluster has a bit too much end play but most of the old transmissions ive done do.id did goe in a couple times originaly but you had to really baby the gas pedal to do it

Sounds like you have electrical gremlins. The starter relay has a fuse, and lots of wires to check. Get a good diagram, see page 386 of the Ford, Lincoln and Mercury Service Manual, 1942-1948. You can get a reprinted manual from the resources page or on the web, try e-bay. When the OD solenoid drops out, the engine is disconnected from the rear wheels, and the signal light goes out. Check connections to relay, solenoid, kick-down switch, and governor. Could be an intermittent in any of these places.
Abe

If you're sure about the connections and the wiring the trouble may be in the solenoid. The solenoid has 2 circuits, an engaging coil and a holding coil. A set of points that engage the holding coil are closed as the solenoid is activated. This action also opens ( mechaincaly) the circuit to the engaging coil. If the points for the holding coil are dirty, broken or mis-aligned or even a broken wire that connects to these points would keep the solenoid from holding. If the OD tries to engage but just won't stay I would suspect this is happening. You can remove the cover from the solenoid and take a look see. Good luck