Reverse Lights & Trunk Wiring Harness

[ChefJRD]

I've had what appears to be a common problem: reverse lights that only work once in while. Sometimes even several times in a row, but then not for a while again after that. After searching through the archives, I found several helpful posts on how to troubleshoot this problem, but I have some follow-up questions I was hoping you guys would be able to help me with.

I first checked the reverse switch by testing for continuity at the connector below the shifter (see pic). I was testing the female connector, with the green and blue wires leading in to it, and it consistently was shorted/continuous when I shifted into reverse which, if I read an earlier post by Javier correctly, should indicate that the reverse switch is operating correctly.

After that I went to the wiring harness in the trunk. I noticed some wires had the insulation rubbed off at the back part of the trunk hinge, though the copper still looked good. To be safe, I taped them up with electrical tape to prevent shorts, but I couldn't find any other issues in the wiring harness along the hinge.

As expected, the electrical tape didn't make any difference. Should I remove the trunk lid lining to look at that part of the harness? Any other suggestions?

I'm heading out soon to go camping for the weekend, so I may not reply right away, but thanks in advance for your help.

[RichO]

Had the same problem about a year ago. Was erratic for a while then one day stopped working completely. Went through the same steps as you- had continuity at the connector in your pic BUT had almost no voltage at the reverse bulb sockets.

Turned out to be that the terminations at the reverse switch were so heavily corroded I was dropping almost all the voltage there due to the high resistence. I just cleaned them up and the lights have been working consistently ever since. The revese switch can be reached from under the car, no need to remove it.

[bill g]

If there is a problem with the wiring in the trunk it will almost certainly be where the wiring flexes as the trunk lid is opened and closed. It is very unlikely to be in the area concealed by the trunk lid lining.

Bill G

[ChefJRD]

Thanks, Rich. I'll give that a try next time I get under the car. Did you have to remove the switch to clean the connectors?

[RichO]

Thanks, Rich. I'll give that a try next time I get under the car. Did you have to remove the switch to clean the connectors?

I did but it wasn't nessesary.