Jump to content

Rear blinkers don’t work.


Recommended Posts

Soooo... I am a brand new owner of a 1990 Jeep Comanche. I am having a wiring problem though... the rear turn signals don’t work. They don’t blink, and they don’t light up when the parking lights are on. fronts work just fine. Come to find it looks like the previous owner bypassed the old brake switch and hardwired a new one to the fuse box. This renders the hazards in functional, but they operate when the wire is unplugged and a fuse put in its place. Go figure, even when the hazard starts are flashing, the rear does nothing.. all the lights light up when I brake and the hard wire is in place but nothing when it comes to signals. I suppose my question is more about the harness and how to hard wire the turn signals at this point??? I don’t know... I have traced the hard wire all the way back to the rear of the car where it is spliced with duct tape.... HELP! What can I do?? I have attached a pic of the hard wire handy work....

EDC948B6-137F-49B4-B4F6-00ED6B320FFD.jpeg

Link to comment
Share on other sites

First thing you should do is clean the ground behind the drivers side taillight.   That is the number one cause for taillight issues.  After that you'll want to try to undo anything "backyard Bubba" did to the wiring.  Report back here after cleaning up the ground on whether that made any difference or not. 

 

One thing I will say is don't hardwire anything.  You should fix it the right way not only because it's the right way but also because you can cause more issues by cobbling something together, similar to what the PO did to your truck.   It also makes it harder for others to help solve issues when the wiring isn't setup the way the factory did it.   Also a voltmeter will be your best friend right now. 

Link to comment
Share on other sites

After you clean the rear grounds, disconnect any trailer wiring, if equipped.

Also your PARK LPS fuse is 20amp, call for a 10amp. Not saying this has anything to do with your problem, but maybe its blowing a 10amp.

Link to comment
Share on other sites

unfortunately i think part of the harness has been hacked out to make whatever he did work. I have no idea what the stock wiring under there is supposed to look like.  I think the fate of the blinkers May be as simple as the fact it is disconnected from the harness right under the steering column

Link to comment
Share on other sites

Sounds like a mess.
With these jeeps in general there is a engine harness, dash harness, & the body harness to which things like taillight harness and stuff like that plug into.

Engine harness and hash harness have one big bulkhead at the fire wall where they literally bolt together. (Behind the fuse box)
In the drivers side kick panel the dash harness leads away from the firewall towards the door jam, that’s around where the body harness begins. There are two plugs in the Cherokee that carry lights, turn signals, fuel gauge, stuff like this to the back of the vehicle.

If you dig deep into troubleshooting I’d try to see if the body harness is getting the power or not where it plugs in to the dash harness.
If it’s ok, then the dash and engine harness should be ok. If it’s not then the dash harness maybe damaged someplace.
Dash harness is easier to source than the body, especially for a MJ I’d imagine.
In situations like these you’ve got to forget where the problem is and work backwards from where the source of whatever signal is wrong.
Sounds like you had cowboys playing in the electrical, could be a reason for it like a wreck or dash fire, or maybe it’s just the cowboy way.

I don’t know the MJ well. I know XJ well enough but some of the folks here probably will have better advice on how to fix this.


Sent from my iPhone using Tapatalk Pro

Link to comment
Share on other sites

5 hours ago, BlackMJ90 said:

So this is a picture of the rear harness. The duct tapped wire is the one hardwired in the front

FCCE9B5B-6D3E-42F4-991B-D1B32B5F9F22.jpeg

Yeah that looks to be your issue there.  Try to clean up those wires and get them hooked back up properly.  If you can get them clean enough to see the color, someone will know what it does, otherwise use a testlight or multimeter to test each wire to see what they do.  If a wire or two don't get power when cycling your signals, brakes, and tails, then you gotta follow it up and find the next problem area. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...