What happens with the dash light?

When you push the button , if the dash light does NOT come on, check the 4th gear switch. With the relay out of the socket, the red wire and a good ground will show continuity if the 4th gear is closing properly.

With the ignition off, the blue wire and the brown wire will show continuity when the shifter button is pushed.

Circuit for OD route.

Fuse to relay socket blue wire feeds relay and shifter button which returns brown to socket.

IF 4th gear switch closed, red wire grounds relay allowing power through yellow wires, one to solenoid on OD, the other yellow to dash light.

Relay socket black grounds relay electronics. Relay electronics determine if button push should close or open solenoid circuit and maintains a closed loop as long as red wire indicates ground through 4th gear switch. IF red ground is lost does not allow closing of relay unless button is pushed. Also allows only one button push about every two seconds to cause an action.

You clutching to get into OD is good. The way the problem reads is you have to go between neutral and 4th a few times to get OD??? IF so you are basically banging on the 4th gear switch until it makes contact. I'd say replace the 4th gear switch on the tranny. Top right of the tranny cover.

Duane,

My 1979 245DL with M47 had the overdrive switch a slide switch in the top of the shifter handle. Is that what you have? OR do you have the push button switch toggle type?

If the slide switch, it is often tht switch that goes bad.

If the toggle type, suspect the relay. It can be resoldered, usually with a good result.

Check under the car. The wire to the solenoid, whether stick or auto tranny, can get damaged and/or disconnected.

Good Luck,

Bob

;>)