On my 544 there is provision for reverse lights even though they don't come on the car. It's a little bakelite bulbous thing on the rear of the trans, activated by the actual internal motion of the reverse lay-shaft (as far as I can see).

My 142 has the overdrive and seems to have the reverse set switch up-top on the shift tower. What component is most likely to fail? Is there a replaceable switch?
It looks like the trans will have to be dropped to get at it. Is there another way?

The reverse lights also have a relay to actuate--under the hood, left side. I believe it's the rearmost relay. It's worth checking before you crawl underneath.

Depends on the size of your hands and your manual dexterity!
Ought to try it in a 122 tunnel!!
You can drop the tranny and move it sideways far enough to get
to it (if you are dexterous) without disconnecting the driveshaft.
The switch is probably OK but the wires get damaged.
--
George Downs Bartlesville, Oklahoma