Tail Light Fuse Problems

[adamiano86]

So about two weeks ago I had my tail light fuse go out in my 1997 Corolla 1.6L - put in a new fuse, it still pops.
I took out all of the running lights, or parking lights whichever you prefer, and tail lights, hit the switch it still pops.
I replaced the relay and the headlight switch.
I traced the wiring in the door jam back to the tail lights to see if maybe a wire got shorted in there.
I loosened the radiator bolts so I could get to the wire harness up there to see if I could find a short anywhere up there.
I also unplugged the wiring from the fuse box by the kick plate that seemed like it was the wiring that would be going to the parking lights.
The headlights do still work though.
I even checked the brake light in the rear windshield and the lights by the license plate, that all seemed good.
I read all the other threads in the forum that people posted with related problems, none of those seemed to help either.
I guess my next move would be to check the lights in the dash itself, since the dash lights go out when the tail light running lights go out, unless anyone can point me in the right direction??

[Bitter]

so you took out all the bulbs and the fuse still blows? its really super common for the dual contact rear bulbs to smoosh together and short.

[adamiano86]

Yeah - I had all the bulbs out and all of the contacts seemed fine - plus all of the brake lights still work when i hit the brake pedal.

[Bitter]

ah, then yes you'll have to hunt down the short, i know how frustrating that can be.

[adamiano86]

Back to the drawing board i guess.

[1jzdreamer]

Inside the trunk behind either side hidden under the carpet are the connectors for the tail light harnesses. Unplug one side at a time and try a fuse. One should pop it and one shouldn't. The at least you know which side is the culprit. Then you can use a meter and trace out the short. It almost always is one of the sockets as bitter said. If you end up needing a new harness, go to a pick a part/wrecker. or I think I have a couple.

[hungt1999]

I had the same exact problem,

it was caused by a short in the elevated brake light under the rear deck pannel, the problem was when I installed a clip for a child's seat, the bolt goes just next to that wire and crushed it causing a short with the car frame

[MightyMax]

I had similar problem.
It locked out my ability to change from Park into any other gear.

So I didn't know this at first, so I follow the repair manual....pulling out my lower dash board and console covers to check the various solenoid and relay switches...all check fine.

Plus it locked out my Passenger Door, so I could not open him.

Come to find out it was a fuse popping.

So I did as an earlier poster said.
I unplugged both tail light wire harnesses....put in new fuse.
Pressed brake pedal, all good.
Plugged in one harness, tested again, all good.
Then plugged in the other harness (this one had a bulb out, so I figured him anyways) and of course the fuse popped.

So I buy new bulbs and pull out the old one, only to see the inside of the bulb is fine.
It is the connector that is shot.
And it had melted its plastic housing/socket, so the bottom contacts were melted together and causing a short.

So now I need to buy a new wire harness and replace it....
For now I just took out the bulb and it works fine.

[adamiano86]

Originally Posted by hungt1999

I had the same exact problem,

it was caused by a short in the elevated brake light under the rear deck pannel, the problem was when I installed a clip for a child's seat, the bolt goes just next to that wire and crushed it causing a short with the car frame

are you talking about right underneath the tail light that sits in the rear windshield? I have had almost every bulb / wire connection disconnected, including by the kick panel by the driver's seat only to have the fuse pop every time I hit the switch - so I am guessing that it's a dead short somewhere, but I am running out of places to look - so if you point me in the right direction Hungt1999 of where your problem was I'd really appreciate it.

[adamiano86]

Originally Posted by MightyMax

I had similar problem.
It locked out my ability to change from Park into any other gear.

So I didn't know this at first, so I follow the repair manual....pulling out my lower dash board and console covers to check the various solenoid and relay switches...all check fine.

Plus it locked out my Passenger Door, so I could not open him.

Come to find out it was a fuse popping.

So I did as an earlier poster said.
I unplugged both tail light wire harnesses....put in new fuse.
Pressed brake pedal, all good.
Plugged in one harness, tested again, all good.
Then plugged in the other harness (this one had a bulb out, so I figured him anyways) and of course the fuse popped.

So I buy new bulbs and pull out the old one, only to see the inside of the bulb is fine.
It is the connector that is shot.
And it had melted its plastic housing/socket, so the bottom contacts were melted together and causing a short.

So now I need to buy a new wire harness and replace it....
For now I just took out the bulb and it works fine.

I had all of the lights out and checked all of the connectors, nothing is melted together and all the contacts seem fine - I had the brake lights completely disconnected and the front side marker lights completely disconnected and I am still getting the 15A "Tail Light" fuse to blow every time I put the switch in to the Parking Lights position.

[MightyMax]

If your dashboard lights are going out as well....
I bet you that somewhere in the dash you have a bad solder point, or a wire is going straight to ground.

When you pull your dash out, check all the wires and make sure none are bare or touching another piece of metal.
Also check all the solder points.....look for some that may have popped off the board or broken contact.

Bout the only other thing I can think of.

[hungt1999]

Originally Posted by adamiano86

are you talking about right underneath the tail light that sits in the rear windshield? I have had almost every bulb / wire connection disconnected, including by the kick panel by the driver's seat only to have the fuse pop every time I hit the switch - so I am guessing that it's a dead short somewhere, but I am running out of places to look - so if you point me in the right direction Hungt1999 of where your problem was I'd really appreciate it.

yes under the pannel at the rear windshield, there is a wire harness that goes to the elevated brake light. Check to see if the wire harness is crushed causing a short with the frame.

Other places I suggest to check is the wire harness that goes along the floor side, longing the door, up near the seat back (remove the rear passenger left side cushion) you will see the main wire harness for all the tail and brake light, remove also the rear left plastic trim (the one with the slot for the rear left passenger shoulder seatbelt), you will see the continuation of the same wire harness

[adamiano86]

Still finding no shorts in the wiring - I haven't attempted the dashboard yet - do you think the rheostat could have gone bad? Seems like an easier check before getting in to the dash.