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Discussion Starter · #1 ·
PLEASE HELP!!!! My truck is a 05 Tacoma prerunner double cab and the green parking light wire has a dead short in it. I cut the wire going into the firewall and wires for the front two lights check good but from behind steering whee to the rear lights I get continuity to ground on green wire. I then cut wire under driver door to help eliminate the rear wire but it checks continuity to ground on both sides of the cut. Where do I go from here any suggestions?
 

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Mambeau / Admin
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Here (attached) is the 2005 taillight / parking light wiring diagram.

Cutting the wires from the light switch wouldn't do anything. Both the tails and the front corner / parking lamps are powered off the 10A TAIL fuse, which in turn is powered off the TAIL relay. The light switch switches the relay, not any of the lights directly.
 

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Mambeau / Admin
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Here's the 2005 documentation on the relay locations. The Tail Relay is in the junction box behind the driver side dash lower panel.
 

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Mambeau / Admin
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It's conceivable, but I don't think that's what's causing the short.

I'm not even sure the continuity-to-ground readings you're getting necessarily mean there's a short. If you cut the green wire to the rear under the driver's side door that would be "upstream" of the B6 junction / splice (see wiring diagram). Meanwhile, the other side (cut wire leading back upstream) is connected to the front parking lamps, which have their own ground points.

If you're applying current to the cut ends in the middle one would expect continuity to ground on both, because each side connects to a ground point somewhere.
 

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Mambeau / Admin
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Let's back up so you can provide some clues to the problem ...

- Were any of the affected lights misbehaving before the fuse blew?

- What was the exact state of the circuit when the fuse blew? Were the lights on, and then failed? Or did the fuse seem to blow when you switched the lights on?

- Have you replaced the fuse (after cutting the green wire) and tried the lights again? If so - what happened?
 

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Discussion Starter · #7 ·
well the lights were fine until recently and we noticed the fuse had blown so we put another in and it blew. Another crazy thing is the the main power wire on the fuse box under the hood will show continuity to the ground on the battery not sure if that sounds correct or not. Please advise where I should start next. Thanks for your help
 

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Mambeau / Admin
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Does your Taco have power windows and door locks? If so - are they all working fine?
 

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Mambeau / Admin
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... Another crazy thing is the the main power wire on the fuse box under the hood will show continuity to the ground on the battery not sure if that sounds correct or not. ...
Do you mean the main power wire from the generator (white or black-with-blue-stripe)? If so, I don't think that's odd.
 

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Mambeau / Admin
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Have you checked all the bulbs in the tails and the front parking lamps? It's possible for a bulb to fail and create a short.

I still need to know if you've tested the circuit (with a new fuse) after cutting the green wire, and (if so) what happens.
 

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Discussion Starter · #11 ·
I tested after cutting and it still blows. I have all the bulbs removed at the moment to check wire harnesses. Windows and locks work fine.
 

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Mambeau / Admin
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OK, then ...

If the fuse blows after you cut the wire (and the wire's not shorting at the cut) the problem is somewhere in the front.

I asked about the power locks and windows because ...

Here (attached) is the 2005 power source diagram. The Tail Relay is bridged to the circuits connecting to the Power Window (P/W) Relay. It's conceivable something gone wrong with the window / locks circuit is drawing enough power to blow the Tail circuit.

If it's not something like this, I'm out of ideas and I can only suspect there's a short somewhere toward the front or maybe in the junction / fuse box itself.
 

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Mambeau / Admin
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Glad to hear you finally tracked down and fixed the sneaky problem.
 
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