Tail light fuse keeps blowing?

[lumberjude]

I can't for the life of me figure out why.

I don't know when it happened or why.

I have a 99 4runner, bought it used, I have not driven it at night until last night when I noticed the gauges would not light up. I did some searching and found that they are on the same line as the tail lights. Also the front corner markers are out, they are on the same also.

I don't know if it's something I did. I installed a CB, it's not tapped in to anything, it goes straight to the battery. I installed some piaa fog lights, same thing they are run straight to the battery. Other than that I put the OEM fog lights back in. There was only one when I got it, I found a set and put the missing light back in, plugged it in the stock wiring. CB works, piaa's work, oem fogs work.

There is an aftermarket stereo in the dash, I wonder if the previous owner tapped into something to power it...but it still powers on and is illuminated (does that matter in this situation?).

I'm just at a loss as far as where to begin.

Any help or suggestions would be appreciated!

 

[submarinepirate]

I had an issue like this with my old Durango. It turned out the wiring harness that had been installed for the trailer hitch was shorting out. Sounds like somewhere you've got exposed wires that're shorting and you'll need to replace it.

 

[KidVermicious]

Yup, you're shorting out somewhere. I just finished playing this exact same game, had my tail light popping intermittently. Turned out to be a shiner on the stereo illumination wire shorting to ground. But your trouble could be any circuit attached to that fuse - start tracing them one by one, it's work but you'll find it.

I'd start with the aftermarket wiring. Trailer wiring, stereo wiring, offroad lights, anything that ties back to that fuse is suspect though.

 

[lumberjude]

I had an issue like this with my old Durango. It turned out the wiring harness that had been installed for the trailer hitch was shorting out. Sounds like somewhere you've got exposed wires that're shorting and you'll need to replace it.

Hey, sweet window decal! They're always sold out when I try and pick one up. I'm actually going to be in Houston this evening until Friday, any nice off-road type shops worth checking out? I'm planning on hitting up 4-Wheel Parts store on 1960 (actually used to live right by there long ago).

Yup, you're shorting out somewhere. I just finished playing this exact same game, had my tail light popping intermittently. Turned out to be a shiner on the stereo illumination wire shorting to ground. But your trouble could be any circuit attached to that fuse - start tracing them one by one, it's work but you'll find it.

I'd start with the aftermarket wiring. Trailer wiring, stereo wiring, offroad lights, anything that ties back to that fuse is suspect though.

Well, turns out I went to put something in the cargo area during lunch, out of curiosity I lifted at the plastic trim to see what's underneath...looks to be a bit of a nightmare, complete with electrical tape. The trailer hitch also has issues, the wires were cut on the hitch itself and a new end was wired in. I think I am just going to remove the hitch altogether (we have a suburban if I ever need to tow anything).

I'm not going to get a chance to check any of it out until this weekend since I will be out of town but I think I now know where to start. This is going to be annoying.

Thanks for the tips guys!

 

[lumberjude]

Just an update, got it figured out.

The mess of wiring was a uhaul trailer lighting harness, don't have any idea why it was put in when it has the towing package.

Anyway, there were splices everywhere. I just took the entire thing out and patched up where the stock wires were tapped into. After that everything works fine again.

 

[fourwd1]

Any time I see a post like yours with screwy lighting problems, it's usually trailer hitch wiring. Luckily fixing the problem is normally pretty easy. Glad it worked out for you.

 

[lumberjude]

Another update...tail light fuse is blowing again. I have no idea what the heck is going on. Everything was working fine. I did put some spot lights up on the roof, but just like everything else they aren't tapped into anything, I ran them straight to the battery.

I'll tackle it again tomorrow.

 

[lumberjude]

I went to address it last night...and everything works.

 

[zak3033]

So I would like to say thank you to all the guys who posted on this thread, I read through it last night when this issue arose and addressed it today after my class. My two cents for anyone who ends up reading this thread in the same situation I was in, start simple and check the bulbs first. I realize most of the people on this forum already know to check those first but that's all it took for my car this go around. All i can say is I'm really happy I didn't have to mess with tracing bad wires. Cheers everybody.

 

[JamesDZ]

If anyone is still here -

So I'm fighting the good fight with my 10A tail fuse that keeps blowing. I replaced the tail light box converter and removed the 4pin trailer harness to be sure. I thought that did it but lo and behold, it blew again this morning.

I still have to repair some cracked wires on the 3rd brake light / rear wiper / rear window but I think that's a different 20A fuse unrelated to the 10A that keeps blowing out. Could those be involved?

I'm not sure where to look next. I haven't changed the bulbs in years, they all still work and have for a long time - could that be the issue? I'm two or three attempts away from giving up and taking it to a shop.