No LEFT signal or brake light

[xjrev10]

Like the title says. This truck has had this issue since I bought it. Now doing the finishing touches on the resto-mod and want it working. I have swapped out the fuse box completely with new connections. Both flashers on the fuse box are new. Connection at tailight harness to truck wiring is good. Ground behind DS tailght is fresh. No trailer lights. I have a turn signal and brake light on passenger side. Only running light on drivers side. What's next to check?

[HOrnbrod]

Connection at tailight harness to truck wiring is good.

 

Are you sure? Did you take apart that connection and check for the 12V at the turn signal and brake light pins? If it's there (it should be), then the problem is most likely in the tail lamp harness or the lamp socket(s) in the left tail lamp. Remove the bulbs and check for the signals at the socket pins with a test light.

[xjrev10]

I took it apart yes. It was butt spliced very shoddy originally. I cleaned everything up good and replaced the butt splices with soldered joints.

 

I did not check for 12 volts at the pins.. I still don't own a meter. Shame on me I know.

[xjrev10]

Are sockets universal for the most part? That was the next step I had planned actually. But.. The parts store guys I deal with are not the best resource for older jeep stuff at all.

[HOrnbrod]

I'd pickup a cheap test light first - a must have especially for lighting problems. And yes, the sockets do go bad occasionally. Also check to make the correct dual-pin base bulbs are installed in the socket.

 

[xjrev10]

Ok. Forgot to mention I did put all new bulbs in also.

[xjrev10]

Been messing with this project most of the afternoon and still have issue. I have power at the jeep side of the harness connector for turn signals in 2 spots. (Bottom small pins. 2 spots. Alone so I can't check brake lights easy) My PS tailight has power on both sides of the socket. (No issues over there to begin with just learning..) My drivers side has power only to the running light side, nothing on the other (signal, brake) side of the socket. I can't find anything goofy or out of the ordinary. There are 2 black wires that come off the ground block on the driver side (not the fuel pump ground spot) that run to the center of the truck. They have push pin type connectors. Unknown if that could be related... I poked the gray/white strip wire on the drivers side with the flashers on and get nothing when I should. I would think that would rule out a bad socket. I also cleaned all of the crap out of the sockets.

 

Hope this makes some sense. I'm at a loss.

[87MJTIM]

If you have not downloaded the 88 Electric Manual yet, here is the link.  http://comancheclub.com/topic/12083-electrical-manual/

 

This has the complete wiring for the 88 MJ.

[xjrev10]

I have a 89 FSM electrical manual I have been using. But hasn't been much help in this case.

[xjrev10]

Looks like I got other issues also. The brake light and turn signals do not work at the same time either.... Ahhhhh

 

Friend of mine stopped over and it sounds like the best plan is to run all new wire from under the dash all the way back.. That's the plan as of now.

[Lee21490]

Looks like I got other issues also. The brake light and turn signals do not work at the same time either.... Ahhhhh

 

Friend of mine stopped over and it sounds like the best plan is to run all new wire from under the dash all the way back.. That's the plan as of now.

Sounds like you have a crossed wire somewhere.