No Reverse Lights

Hey guys what's up? I got a seemingly weird problem with my reverse lights. I tried browsing through the other threads on this site and others trying to find the solution and I couldn't find one that described my problem.

Here's my problem/what I know thus far:

1) Reverse lights don't work

2) I bought and tested a new reverse light switch (manual transmission). The switch itself is fine because when I plug it into the connector and push the spring in, my reverse lights work.

3) When I screw the switch into the trans itself, and shift the truck into reverse...guess what? No lights.

4) I checked the two tail light fuses in the engine bay before I even checked the switch and they check out with a multimeter.

5) There's a 4-prong tail relay i see as well but I honestly don't know how to test it properly. I took it out and saw the tail lights go out and come back on when i put it back in. I'm assuming its fine, but again I don't know for sure.

What could it be guys? Is it possible that somehow when I engage the shifter into reverse, it is not fully pushing the spring on the switch causing the reverse lights not to come on? That seems to be my conclusion. How would I fix it? Thank you.

 

It sounds like the issue is the switch when you put the tranny into reverse. Are you able to see how far the switch is getting pressed after you have it all screwed in? Did you purchase the correct switch (is it the same size/shape as the old one)?

Based on what you said from #2 it sounds like your relay is okay. If you want to test it out remove it then connect 12Vdc (or you might be able to get away with using a 9V battery) to pin 86. Connect ground/battery negative to pin 85. You should measure continuity (short) between pins 30 and 87. When you disconnect the battery from the relay you should not get continuity (i.e. open circuit) between pins 30 and 87.

 

Thanks for the quick response! I forgot to mention that I got the cheapest switch possible since I am a broke college student. The switches look identical in shape and size though, and what's weirder is I just came back from class and the lights work consistently now...the truck has gremlins lol. But that seems logical that the switch itself is the problem. Perhaps I will splurge on an oem one if it stops working again. Thank you! I will test the relay as you described just to learn tomorrow.

 

Glad to help. If you end up with intermittent issues also check the electrical connections for corrosion and clean them off if necessary.

 

How did you take the switch out? It looks impossible to get to from inside where the shifters are. Did you remove the transfer case shifter?

 

The reverse switch is on the side of the transmission, you have to go under the truck to get at it.

 

Having the same issue with mine, though it’s intermittent right now. Definitely a pain point I’ll be tearing into soon.

like you I figured replacing the reverse light actuator on the tranny, it would be a problem solved. Any luck? If relay in the loop, next best guess on replacing.

 

Have you tried installing new bulbs?

 

Haha, now THAT would be hilarious if it was my issue. A serial bulb circuit with one bulb on its way out.

Wonder if the audible sound prompt is also from the serial (if serial) circuit..

this could make sense