Well I've searched through the board and couldn't find an answer to my specific problem.

I've got a 73 Duster with the original 904. I had it rebuilt by my old time mechanic who has rebuilt hundreds of transmissions. I've got it back in the car and am trying to get all the linkages and wiring working over the winter. Right now there is no fluid in the trans. The neutral safety switch has the three prongs and seems to be the correct one. The neutral safety part works fine (will only start in P and N) But I cannot get the reverse lights to come on. If I pull the wire off the switch and short the two outside wires with a wire the reverse lights come on.

Next I tried pulling the switch and with the switch out of the car the lights come on. When I push in on the plastic plunger on the back of the switch the lights go out. I've looked at the pics in the FSM but they don't show quite enough detail. It looks like like there is a half moon shaped piece (manual lever?) that moves when you shift through the gears.

I am thinking that with the switch installed in the car that piece is pushing the switch closed at all times. I've tried moving the gearshift through it's range of motion and the lights don't even flicker.

Could the "manual leaver" have been put together wrong? I assume all the hard parts in the trans will only go together one way and my guy has put it together right. I've seen listings for a "short" switch but they look like the part that screws into the trans is the same length as the one I have.

I've run out of ideas. Hope that long explanation makes sense.

Thanks in advance

Brent

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Arizona Duster in Canada

idont know much about neut switches ive always just bypassed them when they go bad but maybe it is grounding itself out i would imagine someone with the experience of your mech would have done everything correctly good luck

You're probably on the right track in your thinking, and you're just about right on how the reverse lamp switch works. There's a lever on the "rooster comb" which rotates by your moving the gear selector and which both creates the shift position detents and operates the manual valve. This lever bears on the combination neutral safety/reverse lamp switch. The neutral safety function is performed not by pressure, but by selective grounding of the metal pin in the centre of the switch plunger. The reverse lamp circuit is closed when the switch plunger is not pressed. Sounds like either you've got the wrong rooster comb in there, or part of the lever or its plastic "spoon" fitting at the end has broken or fallen off.

One question: Is this a 1969 or later transmission in a 1968 or earlier vehicle? The pre-1969 vehicles used a different switch, neutral-safety only; the separate reverse lamp switch was elsewhere. The rooster comb is different to activate the early vs. late switches.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan

It's the original 1973 trans. I looked at the one picture in the FSM with a magnifying glass, looks like in the reverse position the arm has a dent in it so the switch reverse switch can move out and close the circuit. Squeezing under my car in the cold garage I can't really see what's going on in there too well. I will try again with a little mirror to take a look. Is that part metal or plastic and can it be put together wrong in the trans? Looks like it is all one piece.

Thanks

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Arizona Duster in Canada