Tail Light Fuse Blowing

locknload

New member
I got pulled over the other night for no tail light on drivers side. Assuming it would be a simple fix, I replaced the bulb but it still didn't work. So I checked the driver's front parking light and it was out too. Turn signal, brake and hazard lights all worked fine and everything on the passenger side works fine (including tail/parking lights). So I checked the fuse and it was blown. I put a new fuse in a couple of days ago and thought it was fixed. I checked it again last night and it wasn't working again. Anyone have any advice for where I should start checking first to see why it is blowing only the tail light fuse on the driver's side?

More Info:
2010 Unlimited
55k miles
3.8l
Winch
50" light bar (I haven't spliced into any wiring. Connected directly to battery)

Thanks
 

olram30

Not That Kind of Engineer
Sounds like the m17 fuse. I had this problem when I had my trailer hooked up. Sounds like you have a short somewhere
 

olram30

Not That Kind of Engineer
I do have a hitch and trailer wiring harness. I'll look for any bad wires around the harness, or maybe just unhook the harness for a few days and see what happens.

Follow the wires from the plug on the hitch to inside the body.
 

Havoc40

New member
Had this happen 5 days after owning my '14 Rubicon, towing my 4wheeler out to an offroad park. Replaced the M17 fuse and it hasn't popped again, but I haven't towed anything since then either.

I recently rewired trailer and used LED lights. I went through everything on the trailer after this happened on my Jeep, and know for a fact there isn't a short or ground issue in the circuit. It also worked perfectly on my old truck. Haven't had time to dig into the Jeep's wiring. I do find it odd that when you search this problem there are many people experiencing the same thing.
 

locknload

New member
Follow the wires from the plug on the hitch to inside the body.

Still blowing fuses. Here's what I've done so far:
* Inspected trailer wiring harness wiring. Didn't see any problems but unhooked it anyway.
* Replaced both front and rear bulbs
* Disconnected front and rear bulb assemblies from harnesses to see if something was shorting out in the bulb assemblies

Someone mentioned checking the light plugs with a multimeter to find the short. The problem is that it works fine in the driveway. All I know is that it somehow blows the fuse while I'm driving within a mile of leaving the driveway. If I check it for continuity, wouldn't it read fine? Or, would it show a short once it blows the fuse?

I crawled under the Jeep but I didn't see any wiring. I'm assuming the wiring is running inside the cab (maybe under the carpet)?
 

jeeeep

Hooked
Still blowing fuses. Here's what I've done so far:
* Inspected trailer wiring harness wiring. Didn't see any problems but unhooked it anyway.
* Replaced both front and rear bulbs
* Disconnected front and rear bulb assemblies from harnesses to see if something was shorting out in the bulb assemblies

Someone mentioned checking the light plugs with a multimeter to find the short. The problem is that it works fine in the driveway. All I know is that it somehow blows the fuse while I'm driving within a mile of leaving the driveway. If I check it for continuity, wouldn't it read fine? Or, would it show a short once it blows the fuse?

I crawled under the Jeep but I didn't see any wiring. I'm assuming the wiring is running inside the cab (maybe under the carpet)?

check your fuses, you may have to pull them to see if any are popped but still fused. I had this issue on our Toyota that kept popping the interior dome light and back power windows even though I replaced fuses and checked every connection.
I pulled every fuse to find the culprit was actually the lighter fuse, it had popped and was still fused so it was letting too much amperage through and then causing other fuses to pop.
I ended up replacing 10 fuses that were all popped but still not one had broken clean through.
haven't had any issues since.
It may be a long shot but worth a look since you've checked everything else.
 

westchester13jk

New member
I'm going through the same problem on the passenger side. Took it to the dealership and they traced everything from the rear to the fire wall and didn't find anything. Now the problem is they are saying they won't look at anything in the engine compartment unless I remove all the after market wiring. It's two relays, 1 for each set of fogs. And also the winch wiring. It's not a tremendous amount to remove but really annoying. All of that has been in for 4 months and it just started blowing the fuse repeatedly 2 weeks ago..
 

westchester13jk

New member
So I finally fixed mine.. Wasn't the taillight at all, it was the front marker/blinker. The lens has a hairline crack in it which allowed enough water in to make a mess out of the socket... Had that nice electrical burn smell to it. Just replaced it today and so far so good.. Somehow I didn't notice it was out and apparently the dealer didn't think to check the front either... So glad I didn't start ripping out the aftermarket wiring like the dealer wanted me too
 

jeeeep

Hooked
So I finally fixed mine.. Wasn't the taillight at all, it was the front marker/blinker. The lens has a hairline crack in it which allowed enough water in to make a mess out of the socket... Had that nice electrical burn smell to it. Just replaced it today and so far so good.. Somehow I didn't notice it was out and apparently the dealer didn't think to check the front either... So glad I didn't start ripping out the aftermarket wiring like the dealer wanted me too

wow, good lesson to keep in mind. glad you figured it out before tearing everything apart
 

locknload

New member
Fixed!!

I finally figured out my problem was the front driver's side running light. The marker light for the front fender had a short in the wire near where the harness plugged into the bulb housing. If I had looked up a wiring diagram to see where the M17 fuse powered different bulbs I could have saved myself some time and money. Thanks for the replies!
 

locknload

New member
So I finally fixed mine.. Wasn't the taillight at all, it was the front marker/blinker. The lens has a hairline crack in it which allowed enough water in to make a mess out of the socket... Had that nice electrical burn smell to it. Just replaced it today and so far so good.. Somehow I didn't notice it was out and apparently the dealer didn't think to check the front either... So glad I didn't start ripping out the aftermarket wiring like the dealer wanted me too

No kidding, that could have been a big mess. I've gotten to the point that I don't even want to think about taking something to a dealer... :grayno:
Glad you fixed it. My problem was similar.
 

jeeeep

Hooked
I finally figured out my problem was the front driver's side running light. The marker light for the front fender had a short in the wire near where the harness plugged into the bulb housing. If I had looked up a wiring diagram to see where the M17 fuse powered different bulbs I could have saved myself some time and money. Thanks for the replies!

good info to have, glad you got it solved.:thumb:
 
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