Thread: Newest issue: Reverse lights!

I noticed this morning in the reflection of my car's tail lights in a chrome bumper that my reverse lights were staying on. Got home, cut off all exterior lights that I could, left it in park, and yep, reverse lights stay on! Any common experiences with this? I'm thinking not in the MFS or the headlamp switch, as neither controls the reverse lights. I looked at the range switch on the top of the trans, and there was nothing outwardly apparent, plus from what I've read, those are uncommon to have issues. Any other good places to look before busting the multi-meter back out?

check the harness that leads from inside the trunk to the trunk lid. where it comes through the body and bends it tends to break open, most of the time stuff stops working, but maybe its keeping power to the lights.

or it could have something to do with the shiftier. id put money the rev lights are triggered by the shift stick.

till you figure it out, just pull the bulbs out.

Along those lines, I pulled the rev. light fuse to keep them off for now. They seem to come on with keyed power, so I'm wondering if it's a short to hot with something like the power windows or stereo, or fuel pump.

open the trunk and take out the right rear taillight assy. there is a bulkhead passthru that can become corroded and create short to ground.

I had this happen with brake lights that would stay on. I cut the wires and rebuilt the bulkhead passthru to fix it.

MG

Over the weekend I pulled the bulkhead fitting through, and checked the wires for a good 6" in either direction of where it passes through the trunk. Aside from some road grime accumulated in the plastic conduit, the wires looked fine. No breaks, exposed wires, obvious corrosion, etc. I cleaned it out where I was checking, and taped the conduit back in place, and plugged one of the bulbs back in, and it was working fine, so I plugged the other side in, and they were both acting like they were supposed to.
The only other thing I found throughout my efforts, was that there was water that had leaked in somewhere and accumulated under the carpet in the passenger side rear. I've already done the fix for water accumulating in the front, and that carpet was dry, so there's another issue to track down, but I wonder if water accumulating where those wires all run through the inside of the body are part of the reverse light issue, and it only stopped because I got the water out? I also checked the wire loom there and didn't see anything, but it's possible I just missed it.

the bulb sockets can go bad from being wet too if the tail lights hold water like most do.

Originally Posted by Scottydoggs

the bulb sockets can go bad from being wet too if the tail lights hold water like most do.

So I guess the best option if that's the case is to silicone the seam on the lights and clean the socket, assuming it doesn't need to be replaced? I noticed a little browning around the sockets, like from too high of a wattage bulb, but the connections inside actually still looked pretty shiny.

Originally Posted by onxy

I actually had this issue when i replaced my transmission a couple weeks ago. Mine ended up being the module on top of the trans. I had the original on hand so it wasn't a huge concern, but it seems like the symptoms you're experiencing.


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That is the range selector switch that I mentioned in another post somewhat relative to this, but I've mostly read they don't go out. That could still be my issue, honestly, but harder to trouble shoot when it's not actively doing whatever, and mine stopped before I got to that switch to check it. That will likely be where I start if/ when my issues start again.

You say yours stopped before the switch... can you elaborate on that please.

In looking at the 7 pin connector there is power in and then the reverse lights output from that same connector. To test, I'd check there is power in at the orange wire and after blocking the wheels and putting it in reverse with engine off you should have output on the reverse lights pin. If you aren't getting power in...that's likely your issue. If you do have it and don't have power out then it's the switch or the adjustment of the switch. If you have output to that reverse wire and nothing at the back of the car, that's a long way to trace the wiring.

Looking at the pinouts again, I'd also check that yellow has power with ignition on. The reverse output could come from either yellow or orange.

Originally Posted by BillBoost37

You say yours stopped before the switch... can you elaborate on that please.

In looking at the 7 pin connector there is power in and then the reverse lights output from that same connector. To test, I'd check there is power in at the orange wire and after blocking the wheels and putting it in reverse with engine off you should have output on the reverse lights pin. If you aren't getting power in...that's likely your issue. If you do have it and don't have power out then it's the switch or the adjustment of the switch. If you have output to that reverse wire and nothing at the back of the car, that's a long way to trace the wiring.

Right, by stopped, I mean that the issue I was having all the time if the key was on......stopped. I had plugged both bulbs back in "just to see" after checking the wiring where I did, and getting the water out of the rear floor pan, and they did not come on with keyed power. Then when in reverse, they came on, as in functioning properly. So I stopped even messing with it at that point.

So *IF they are currently functioning properly, then there should be power at the orange wire and at the reverse lights pin ( I believe light green wire) when the car is in reverse. I would think that under all circumstances there would be hot at the orange wire when the key is on, assuming the reverse lights come on at all right? it would just be a matter of whether it was lighting up (getting power at the b/u pin) beyond when it's supposed to, indicating the switch.

Then again, like a lot of folks, circuit trouble shooting has never been my favorite, so I could be 100% incorrect....

* or yellow.

If they are working.. how can you be wrong? I love the fixes that cure themselves and since the only thing you seem to have done is clean the sockets and dry out the tails. I'd bet it's at the tails.

Originally Posted by BillBoost37

If they are working.. how can you be wrong? I love the fixes that cure themselves and since the only thing you seem to have done is clean the sockets and dry out the tails. I'd bet it's at the tails.

Could very well be, but the leak hasn't come back, and the b/u lights are working properly, so I'm going to leave it until they start acting up again. Now all I need to do is nail down the fuel trim issue that I'm having and do an ATF fluid and filter change with shift kit, and on to more enjoyable ventures with it!