1G Reverse light switch not working: Can it be fixed, or replace?

[XC92]

I'm just about done getting my '92 Talon TSi AWD manual in driveable condition, and the last steps that remained were checking all the exterior lights so it passes inspection. Everything checked out except the reverse lights. So I pulled the plug from the trans and jumped it with a wire, put the car in reverse with the key in and on but the car not running, and the reverse lights came on. So it's the switch.

First, is there ever a case where the switch is actually fine and the problem is in the trans itself, and if so what generally needs to be fixed or replaced?

And second, if it's the switch, I can order a new one for around $20-$25 online, a bit more from a local Mitsubishi dealer, but I'm wondering if these things can be fixed. It appears to be pretty easy to remove, just a large hex bolt, so I'll pull it tomorrow and have a look-see. But if anyone's fixed one of these, I'd appreciate any feedback. I prefer fixing to replacing when it's all the same.

 

[luv2rallye]

First, is there ever a case where the switch is actually fine and the problem is in the trans itself, and if so what generally needs to be fixed or replaced?

Know that on at least the 2g the washer under the backup switch must be there and the correct thickness (0.037") for the switch to work (even if the switch is brand new). So pull out the switch and check if it's working with an ohmmeter. If so try the correct washer.

 

[nismojones]

The switch is just a spring-loaded ball that makes contact when the shift lever is moved there. Not a lot to go wrong but its a sealed switch and non-serviceable. You can pull it out and not lose fluid, and check to see if the shift rail is moving through the range to hit the sensor ball, which it likely is (you would have issues engaging reverse/1st).

 

[Mech Addict]

So you jumped the connector and then put it in reverse? Seems like the lights would be on continuously with the jumper, and gear reverse engagement irrelevant...

You should be able to check the your installed switch function with an ohm meter, and the car not running, but shifing in and out if reverse.

 

[XC92]

No, I jumped the wiring harness plug that plugs into the trans reverse switch, which simulates what the switch does when in reverse. I.e. it closes the circuit (I'm assuming that it's a NO switch, as there's no way to tell with the broken one if it's NO or NC as there's no continuity either way).

This turned on the backup lights, with the key in the ON position and the engine off, and confirmed that the wiring, circuit and lights are fine and the problem is entirely in the switch or trans.

Taking the switch out confirmed that it's the switch, not the trans or a missing washer (which wasn't missing and is pretty thin, like 1-2mm just eyeballing it).

I'm ordering a replacement aftermarket part from Advance Auto and will pick it up tomorrow and see if it fixes the problem. It's just $13. The OEM is nearly $30 but I figure it's just a switch so it's not likely to go bad any time soon.

I just need it to pass inspection. If it goes bad after that I have time to get an OEM and return this one with the car legally parked on the street.

 

[steve]

Sounds like you have it figured out. This is for future reference.

You must be logged in to view this image or video.

 

[XC92]

I seem to be answering a lot of my questions this week. Glad to be of help to myself!