Strange Electrical Occurance

I have a 1900 XJ Limited. I don't know if there are engine options so for the sake of calirty, it has a 4.oL. I was just notified (by the local PD) that my running lights were not working. I went to check it out tonight and found a blown fuse (15A in a 10 A circuit). I swapped another 15A for reasons that can be discussed later which promptly blew. Makes sense. So, since the Chiltons I have shows the circuit as a 20A curcuit, I plopped in another 20A, midly concerned about excessive current draw on the circuit. That didn't prove to be a problem. The 20 A fuse blew just as quickly as the 15A. So, after contemplating the issue, I resorted to the fail safe rule. I went back to where I was working on it last and looked for the items I had touched. I was changing speakers in the lift gate and while doing so noticed a barrell plug (blue in color) that was disconnected. I thought that I had knocked it loose so I plugged it in. Come to find out, that was causing excessive draw on the parking, tail light circuit causing the fuse in the block to blow. Does anyone know what that barrell plug does (other than blow my fuses)?

THanks,
Jason

I didn't know they made an XJ in 1900!!:wave: I'll look in the 1990 FSM in a little bit and see if I can find something!

Just guessing. A power feed for the alternate tag light, if you have a rear mounted spare the tag and lamp go to the side of the gate.

Rev

Looked in the 1990 FSM but didn't dig real deep. Only shows 2 black connectors, nothing blue. Maybe a little more info, wire colors, shape of connector etc.

So your local pd is giving you greif over parking lights not working?Mine are not working but my side markers are so I said screw it.....man I hope I don't get hassled by my local pd....

The connector is a single barrell plug on the driver side of the lift gate. I may have the colors wrong. I will check today. What are the black plugs for? It was pretty low lighting and my eyes could have been tricked. Sorry about the 1900 thing. I ain't the best typist, as you can tell. UPDATE: I replaced the fuse with a 10A lfuse because that was what the block labeled the circuit for. The 10 A worked for about 10-15 mins before it blew. I have to get some more fuses, but I think I am going to try a 15A and also ensure the barrell plug isn't making contact with any metal. That may be causing a current spike and blowing the fuse. I hope this fixes it otherwise its off to the races chasing wires and connectors.....ughhh.....

jeepguy68 said:

The connector is a single barrell plug on the driver side of the lift gate. I may have the colors wrong. I will check today. What are the black plugs for? It was pretty low lighting and my eyes could have been tricked. Sorry about the 1900 thing. I ain't the best typist, as you can tell. UPDATE: I replaced the fuse with a 10A lfuse because that was what the block labeled the circuit for. The 10 A worked for about 10-15 mins before it blew. I have to get some more fuses, but I think I am going to try a 15A and also ensure the barrell plug isn't making contact with any metal. That may be causing a current spike and blowing the fuse. I hope this fixes it otherwise its off to the races chasing wires and connectors.....ughhh.....

Click to expand...

Looked in the FSM again. There is wiring in the liftgate for license plate lamp, washer,wiper set up, heated rear glass, third brakelight. Are any of these not working? Can you get a picture of where the fuse you are replacing is, may be easier to determine what is affecting it.

jeepguy68 said:

The connector is a single barrell plug on the driver side of the lift gate. I may have the colors wrong. I will check today. What are the black plugs for? It was pretty low lighting and my eyes could have been tricked. Sorry about the 1900 thing. I ain't the best typist, as you can tell. UPDATE: I replaced the fuse with a 10A lfuse because that was what the block labeled the circuit for. The 10 A worked for about 10-15 mins before it blew. I have to get some more fuses, but I think I am going to try a 15A and also ensure the barrell plug isn't making contact with any metal. That may be causing a current spike and blowing the fuse. I hope this fixes it otherwise its off to the races chasing wires and connectors.....ughhh.....

Click to expand...

Like the Rev said, that one on the driver's side is the feed for the license plate light that mounts on that side, if you have a rear tire carrier.

Just out of curiosity, did you pull off any of the kick panels at the door sill bottom, to run speaker wires? I had almost the same thing thing happen and the cause was when I replaced the screws for the kick panels, I screwed one through the wiring harness. If it isn't in the tailgate, this may be a possibility.
The last time I had my lift gate apart, I had a look around with the a mirror and a flashlight. There were many things that were fairly corroded. I had a wire hanging on my 88. And in the wifes 95, the rear window washer hose was hanging and spraying washer fluid all over the inside of the lift gate.
It may be something less obvious.
There are many places the taillight harness (behind the lights) can be cut or chaffed on the sheet metal.

The blue wire in the lift gate is for your Plate light.

I will snap a pic soon. I can't do it right away. I have two large projects for work comming due faster than I can comprehend. I haven't checked the plate light or third brake light for proper functioning. I will do that in the morning.

I do want to say that it is very nice to have this forum to pose my hurdles to and get so much help in overcomming them. Thank you to all who have contributed.
Jason

From what I've been told that wire is for the mercury switch or something like that, just leave it unplugged and you'll have no problems. I plugges mine in, hit the brakes and the fuse blew, unplugged it and it was normal again...Go figure

I know this is an old thread, but I am putting in my 2 cents becouse this thread just helped me resolve my issue. I have a 1990 cherokee I just bought and I was putting on the rear panel when I saw this Blue and Black wire unplugged that looked like it should have been plugged in. So I plugged it in and a few days later I noticed that the dash lights didnt work. I tested the fuse and it was pulling almost 18 volts. After searching and finding this thread, I unplugged that connector and What do ya know, it stopped pulling 18 volts. Now it pulls just 12 volts and everything is good.

Keep searching, this is an AWSOME forum.

I'll check tommorrow but I am pretty sure I plugged the same thing in and that explains why I had to rewire the whole park light circuit from the headlight switch to the lights...

That's probably it....I made the same mistake a few years ago on an old 86 xj.