Tail light fuse/parking brake issue!

Hey folks, I’ve been trying to figure out why my tail light fuse keeps blowing in my 2012 Prerunner. I picked up some light-up fuses, and thought I had it figured out, but I guess not. So far, I’ve checked all tail and license plate bulbs for corrosion and noticeable wiring issues, and unplugged my trailer lights. (The previous owner installed a 4 pin connector.) I thought I had it figured out, since I hadn’t blown a fuse since I did that a few days ago, but when I went to leave the house tonight I popped one when I released my parking brake…

I put a new one in to test it, and it turns out, when I set and release my parking brake with the headlights off, nothing trips, BUT if I release my ebrake with my headlights on, it pops the fuse every time. (I tested both 3 times to make sure it wasn’t just a coincidence.)

I’m at a loss here, as electrical stuff isn’t something I’ve dealt with much in the past.

Any help or guidance I could get to try and narrow it down would be much appreciated.


Thanks!

- Michael

 

Have you inspected the parking brake pedal and linkage to make sure it's not pinching any wires?

 

I felt around and didn’t notice anything, but I’ll try and look closer tomorrow.

 

When the previous owner installed the 4 pin trailer harness, they had to install a converter box with it since you have separate (amber) turn signals. Those converter boxes go bad all the time and cause all sorts of problems. Make sure you take that out of the system while trouble shooting.

 

This happened to me as well. Trailer brakes shorted and caused blown fuse and lighting issues.

So if you have trailer brakes... start there.

 

Unless it's factory the after market stuff has two issues poor quality and operator install.

 

4 pins don't have brake wring, only lights.

 

You are correct. I just had lights.

 

I completely forgot that it does have a Takonsha Voyager trailer brake setup installed as well, but it and the trailer light adapter have been unplugged for a few years. The wiring is still there from the brake system, though, so I will double check and see where that runs. I don’t need the trailer brakes so I could uninstall that whole thing.

 

I think this was it. I felt around when it started happening and didn’t notice anything, but this evening I was able to reach way up in there and felt two wires that were dangling where they definitely could have been making contact. After stuffing them back up under the dash, I was able to set and release the parking brake multiple times in a row without tripping anything.
Prior to moving them, I tripped 3 in a row while releasing the brake after testing other things.

Thanks for the suggestion!

 

Good catch, but you're not done yet. Now you need to pull those wires back down and identify where the insulation is missing, then repair it. Otherwise, your problem will return - probably at the worst possible time.

 

y

Yup. That’s tonight’s project.