Weird turn signal/brake light problem

Strange deal here. My turn signals do not work unless I pull the hazard switch then they work normal and when doing this the hazard lights dont work. The hazard lights dont work at all. Any way I got to poking around and found that both blinker modules work fine but that the hazard fuse under the hood was blown. I put a new one in and the hazards work but it also turns on the brake lights. However, the brake lights do not work at the pedal. So in a nutshell, I have no brake lights, turn signals or hazards but the signal work when the hazard switch is pulled.

^^^^^^

Most likely suspect is a bad ground somewhere, perhaps in the brake light circuit, but possibly in the signal circuit. What often happens is that, lacking ground, the current tries to find its way to ground through one of the other circuits, so you get the anomaly of signals lighting the brake lights, etc. Probably the best way to check this is with a meter or test light at the taillight end, and start tracing back.

The most likely bad ground is the one behind the facia panel where the spare tire mounts. It can cause some real wierd interactions with the lights.

I've had some really weird problems like this when my converter box that you have to use for your trailer wiring has gone bad.

Dragline said:

I've had some really weird problems like this when my converter box that you have to use for your trailer wiring has gone bad.

Click to expand...

That and someone hook up a 4 wire trailer system without a converter.

my 87 MJ does the same thing, when I pull the headlight switch my turn unless the hazard switch is puled. Pulling the hazard switch casues both my dash indicators to light. I haven't traced it down yet, thanks for the info.

Got it fixed. My coax for the antenna for the CB got between the brake pedal arm and the switch. It got so squished that it pushed the switch out causing it to turn on the brake lights. I guess that it also for some reason blew the fuse. I moved the coax pushed the switch back where it was suppose to be, put a new fuse in and all works now. It is weird cuz I thought it was something I did when replacing my drivers side headlight. I got it in and right after that I noticed the siganal problem. Just a coincidence I guess. I can't see why the fuse blew though? The coax sheath was pinched enough to show the braid but that would be a ground anyway and to my knowledge that wouldn't cause a short of any kind. The damn braid is grounded on the chassis any way. So I am a baffled why the fuse blew.
Brett

I am also having the same problem and I can't seem to find to cause. My turn signals work but the parking lights wont say on. Has anyone had the same issue and able to locate the issue