Hi folks,

My 1967 122S has a few minor issues I need to resolve to get it inspected so I can insure it. The one I'm currently interested in is the white reverse lights. Right now the wire is unplugged from the relay in the engine compartment. When I plug it in, the white reverse lights stay on.

I put the front of the car up on jack stands just now to get under and look, and the switch is right at the back of the transmission where it connects to the overdrive. I can't see any way to get at the switch without pulling the motor/transmission.

Except! What do you think of this idea (which was recommended to me by a guy who hasn't done it but thought it might work):

I could put the motor/transmission on a jack, take off the driveshaft, and loosen off the front motor mounts and the transmission mounts, and angle the entire motor so the transmission is dropped down a bit, giving me access to the switch.

Would this work? I'm quite worried about all the wires and tubes that are exactly the right length that I could possibly damage by angling everything down a bit.

Even if I got to this point, I'm not sure what the issue is, and I'm worried I'd replace the switch and get the whole thing together again and it still wouldn't work. This is what happened to the previous owner. The switch is a new switch. (EDIT: I realize that it's just a switch. So I should be able to put a meter on it somehow).

Thanks for reading this far if you have. Any suggestions would be well received.

I'm sitting here stewing over this, wondering if it could be the relay. But if that were the case, the reverse lights should stay on all the time, no matter if I've got the tranny switch connected to the relay or not.

EDIT: I just went back out and grounded the relay terminal, and the reverse lights go on. So now that I see how the relay works, this tells me that either there's a short in the wire on its way to the switch on the transmission, or the switch is stuck in a closed position somehow.

I guess my next step is to unhook the wire from the switch. I can reach around and do that I think, but the trouble is going to be getting it back on by feel. I guess if I unhook it and it's still grounding out then I've got a short somewhere in the wire on the way to the switch. I assume it's just a normal male/female connector of some kind.

Any suggestions are appreciated. Thinking "out loud" like this is super helpful.

You're on the right track. Check for the wire being pinched and grounded against the body somewhere, but aside from that it's probably that the switch is stuck closed.

and not sure about a 120, but on a 240 dropping the xmember and tilting the motor/tranny is the best way to access that switch. You might be able to do it with a deep socket and the right extensions without having to move anything, helps to have a switch in your hands to test fit the socket.

Thanks for that, and thanks to Canuck_122 for
his initial help getting me started over PM.

You can get the aluminum can off of there without tilting anything. Just get a stubby screwdriver and feel around. There are pictures on the brickboard somewhere... they can go bad, thus the change in switch style for the M45/46. You checked the relay right?

I checked the relay by grounding out the terminal, which causes the reverse lights to come on. So hopefully that's how it's supposed to work.

I'll give what you're saying a try first before I do anything drastic. I can see the edge of that can you're talking about from under the car. I felt around and it's pretty grimy under there, but hopefully I can get a phillips screwdriver.

Thanks. I'm going to try this tonight.

Some observations:

- It's easier to look at this thing by using my wife's little makeup mirror. I took a photo of it through the mirror but dropped my camera afterwards and broke it

- With the overdrive bolted to the the transmission, there's not enough room to get a screwdriver in there. I can fit a screwdriver bit in there, so I'm going to have to search for a tiny little wrench that will let me turn the screwdriver bit. Any tool suggestions appreciated. It's super tight in there, so even an allan key fitted to the screwdriver bit is too big. I think even if I lowered the transmission a bit the overdrive is still in the way.

- The shift boot is exactly above the reverse light switch. I can't get to the screws since they're on the end of the unit, but I'll be able to put the wire back on once I figure out how to unbolt and bolt the thing on.

- I'm considering rigging up a switch under the shift boot that grounds out the relay when the shifter is in the reverse position, since the wire is right there anyway.

Oh, I didn't realize you were running an M41. That changes my previous advise slightly. With this transmission installed you need to tip the engine and transmission back to get at the switch.

Unbolt the drive shaft and slide it back as much as you can. Put a jack under the transmission (by the tranny mount is fine) and unbolt the cross member (4 bolts). Then loosen the engine mounts (the one on the exhaust/intake side is easier to do from below). Then lower the jack under the transmission mount. This will tilt the engine/transmission down. It will come down far enough to get in behind the OD and get at the two screws.

Sorry for the previous instructions.

No problem for any advice, I appreciate you taking the time to look at this.

It may be a fool's errand, but Canadian Tire sells a little screwdriver ratchet set that is probably small enough to get in there. I got good at lying on my back trying to unscrew it last night, so I'm going to stop at the store on my way home and pick up the tool and try it. It will be a quick experiment, and if it fails I'll follow your instructions on lowering the transmission a bit.

Much thanks.

It's not getting it out that will kill you...it's getting the screws back in when you've got no clue where they are going...

It took me 2 hours to swap transmissions the last time I did it. Why not just pull the transmission out and be done with it? Seems all this messing around with ratchet screwdrivers and trying to get it back into place when you can't see where the screws go is a recipe for total frustration. Once you've got the driveshaft disconnected and the crossmember loose it takes about 15 minutes more to disconnect the clutch, shift lever and 4 bellhousing bolts...

Just my 2 cents worth...

Hey guys,

I was able to get the switch out, and back in. I'm actually not bad at it now.

The little spring inside the switch was bent way over and contacting the bolts that hold the thing on, making a constant ground, thus causing my reverse lights to stay on. At least I assume that's what was happening, because when I looked in there it was bent way over against the bolt.

I put the thing back on, and no reverse lights. I took it off, shifted into reverse and felt around up there to make sure the contact is coming out, and it is. So after twisting the lead around to situate it and playing with the spring, I can't get it to pass current through between the spring and the lead on the outside of the switch (I checked with a volt meter). I get 100% resistance when I put a voltmeter on it. That spring is super flimsy too. Seems like it's waiting to fail. I'll mess around with it some more, but I'll likely just order a new switch.

The great thing about all this is that this is fixable. I was worried I'd get the thing off and there would be some other issue.

That's the do-hickey I was explaining...mine was the same way. As soon as I bent it back into place it worked fine until I changed the transmission. Bend it so it is hanging straight down. What happens is the rod that holds the reverse selector comes out of the transmission when engaged and touches the spring.

There are a couple of options for repair. A small piece of speedo cable would work (get a repair kit at NAPA for a random speedometer) and remove the switch and put the speedo cable in as a replacement for the weak spring.

Bend it back - drive it.

Order new.

Fixed, finally. I ended up calling John Paulsen out in Springbank, who I imagine some people around here know, and he sold me a new one. I got to know him when I had a '68 142S and I'm pretty sure he's got every part there is.

I also hooked up a rear brake light that wasn't working, and I think the car should pass inspection now. Thanks for all the advice and patience.

When I was first trying to understand all this, I came across a few people asking about it, but no real answers. For future googlers looking to solve this problem, here's the tools I used to get the switch off in such a tight spot: