How do you fix reverse lights on a 1989 jeep?

Answer 1

It is on the same circuit as the brake lights, but if they are not working, and the bulbs are good your switch needs cleaning or adjustment.

Attempt this first since the switch costs nearly $300 bucks.

On the passengers side of the trans just behind the bell housing there is a fan shaped switch, loosen the 12mm bolt ( smaller of the two, and rotate the switch while a friend checks the lights. this problem is usually accompanied by an occasional inability to start the vehicle, but can be cured by jiggling the shifter.

While adjusting the switch make sure that the vehicle will start in park as well, remember to block the wheels while testing the back up lights, engine off, key in run but not start, shifter in reverse, move switch until lights come on.

Once you find this spot, hold it in place and have your helper check to make sure it will start. This may take several tries to get both working correctly.

If you have no luck the switch may be dirty, this happens a lot. Hold the post to the bottom large bolt still while you loosen the nut, then remove it, then remove the 12mm adjusting bolt on top, remove the wire connector and pull the switch away, remove the bolts on the switch and separate the halves, use electrical contact cleaner and maybe some q-tips to clean all the copper connections completely apply di-electric grease and reassemble, refit to the trans and readjust so all functions work, this switch controls back up and start safety.

Caution! always hold that bottom bolt while tightening the large nut, this is connected to the gear adjuster and you could damage the internals if it isn't secured while you do it.

I just did this procedure on my '91 Cherokee, and it works great, but, I would make the suggestion to use a multi meter and run a continuity test in each gear position. you should read at 000 in each gear position at the connector and you'll need a diagram to tell you which contacts you should be checking for each gear position, (this can be done without climbing under the vehicle) if it doesn't read 000, CLEAN IT. There are charts on the net that tell you what position is what, and where you should have continuity. if you can't find one I could send you a pic of it.

The connector is on the firewall in the engine compartment on the passenger side. (there are two that look similar and have the same number of contacts but are different colors. I believe it was the black one on mine, the other is gray) when you clean the switch it's not sufficient to only use contact cleaner, you need to use it AND GENTLY scrape the "wiper contacts" and contact "rails" with a razor or something similar until they are smooth and shiny like a new penny, (don't gouge them, or remove too much material) otherwise you could end up either doing this again, or dropping $300 on a new switch when you didn't need to.

it really isn't that hard to do this job but, remember you need to test ALL gear positions because it can fool you into reading as good if you only test it in one gear position. while another has a lot of resistance to it.

definitely use di-electric grease on any and all connections, and I actually used it to lube the switch innards as well, we'll see how that works over time. make sure to remove and scrape clean the spring loaded contacts on the wiper arm and remove all the crud from the springs so they can run smoothly.

remember as well, that this switch IS ADJUSTABLE, so you may need to adjust it once it's back on the transmission. it's just a one screw adjustment, and you will need to run the resistance/continuity test again to confirm it's in the correct position for EACH gear. good luck!