The reversing light switch on my 123GT is not working. It is the switch with the aluminum cover which screws onto the back of the M41 gearbox just above the output shaft. It has 2 phillips screws.

Everything else works fine, if I ground the correct pin on the relay the lights come on.

I can see the switch if I remove the rubber bung from the transmission tunnel, also if I crawl under the car I can see it as well.

Looking at the GCP diagrams it appears that there is a contact in the side of the aluminium cover which hits one of the gearbox rods when in reverse. They are available and I ordered one.

It's a small rubber nubbin thing with a spade connector on one side and a bolt thread on the other.

My problem - is there a trick to replace this? Do I have to drop the transmission ? Is there a way to undo the 2 screws from the hole in the tunnel? Can I replace the nubbin only or do I have to get the whole switch out?

Thanks everyone!

Andrew

Pull the 2 screws for the aluminum shift rail cover to change the reverse light switch.

If the gasket tears, trim the remnant and use oil resistant silicone on the edge of the aluminum shift rail cover and on the underside of the head of the 2 screws. Use a little blue Loctite on the threads of the screws.

FYI, I usually have those switches in stock.


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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

That's weird, the switch on my 123 GT failed also. You have to drop the back of the M-41 down to get to the 2 phillips screws holding the switch. Or at least I did after trying every other possible way. It's probably a broken spring inside the aluminum cover: this is what grounds the circuit when the reverse gear selector rod touches it.

You do not have to drop the trans to remove this item. offset ratcheting phillips screwdriver.or a phillips tip in a socket, or in a a box end wrench

Thank you all for your responses. After an hour of fiddling with offset screwdrivers etc and using special swear words, my friend Mr. A. Grinder and I made a neat access hole in the top of the transmission tunnel.

30 seconds later the switch was off, it turned out that the little spring contact inside was pristine...it didn't work because the switch case was installed the wrong way.....thaaaanks previous owner.

Bit of a clean, splodge of instant gasket, and presto...problem solved. Nice new cover plate from a bit of steel and no one will ever know the difference...

And I soldered the connector onto the switch too....don't want that bad boy coming off.

Admittedly, I was a bit reluctant to hack a hole in my car, but given the rough life it has led prior to my TLC I did not feel so bad. Had it been a concourse vehicle it would have been different :-)

I can't figure out how to upload a picture but if anyone wants reverse light switch porn let me know and I will send you one.

AndrewofPA