Tail lights dead, need help!

[Big rob]

I have a problem, since doing my manual GZ20 conversion last week my tail lights wont turn on when i turn on my head lights. Either will the dash lights etc. I checked the fuse box in hte kick panel and a the fuse for "tail" was blown. I then proceeded to put another fuse in and it imeadiatly blew up! So to me that suggests a short.
During the conversion, i can see how anytihng i did would affect the tail lights. I only hacked the auto transmission loom and reconected some ground wires under the car to the block when i removed the auto.

Could some one give some pointers on diagnosing this problem.

THanks alot,
ROb

[AndyTTR]

A lot of people's dash lights dont work after they've been fiddling with the dashboard because they forget to plug the dimmer switch back in, but that's probably not what's going on here...

So your brake lights work, but the tail lights dont? Maybe you damaged the loom up in behind the steering wheel when you installed the clutch / brake pedals? All the wiring for the lights / switches would be up around that area.

[crownv8]

The dash lights and the tail lights run off the same fuse. You say manual conversion, so I assume you did work under the dash area to fit a clutch pedal assy. I would say you have either damaged a dash light wire or caught one between two metal surfaces as you have tightened something.

First place to look anyway.

Shane.

[Big rob]

ok thanks guys.
i guesss i'll have to get a wiring diagram or something out. I guess this is going to be tedius .

[crownv8]

Best bet is to just lay down under the dash. Something we all love to do. Then look where you have mounted the clutch assy and just made sure there are no pinched wires.

[Adam_Cressi]

Check the "tail" fuse in the fuse box while ur under there

[Big rob]

Check the "tail" fuse in the fuse box while ur under there

read up a little

[Adam_Cressi]

my bad sorry dude

[BradW]

There will also be a dash light feed at the shifter for the gear selector indicator on the auto.
Another place for a short. Try disconnecting the dash light dimmer switch and see if the fuse still blows. If it doesn't then the short is definately in the dash light wiring.

[craigy]

I've had this problem a couple of times and almost every time its been removing and refitting trims and covers etc There is a good possibility u have hit a wire with a screw. Also if youv'e mounted anything in the car like a gauge or ecu or u may have hit something whilst fixing it.
Good luck.

cheers
Craigy

[Big rob]

thanks guys, wont have a chance to look till wednesday but all your help has been great

[Invid]

it could be a pure coincident (I know my car is full of them) but have you checked the power/earth wires on your tail lights, they may have shaken loose while swapping boxes over.

[Big rob]

ok been looking round and no luck. Heres the deal: brake lights work when brake pedal is depressed. Reverse lights work. When you turn the head lights on they come one but neither dash or tail lights come on. Been 'jingling' all wires, looked at pedals to see if any crimped cables but cant see any . When headlights are on, getting a constant 12v across the fuse terminals.

Dont know what else to say, besides that under the car we hacked the auto loom and there is one wire on the block that we removed that was reatached before the car was finished.

[BradW]

Try disconnecting the dash light dimmer switch and see if the fuse still blows. If it doesn't then the short is definately in the dash light wiring.

Have you tried this.

You have a short in your tail light circuit. This powers your tail lights, front park lights and dash lights. You need to isolate different parts of this circuit to narrow down where the short is. Start with disconnecting your dash light dimmer and see if the fuse still blows. If it does the short is not in the dash lights. Next try disconnecting the wiring to the rear lights. There's normally a plug in the kick panel for the rear wiring harness. Again see if the fuse blows. If not then the short is not in the rear wiring. If you disconnect a circuit and the fuse doesn't blow then the short is in the circuit you disconnected.

Tracing a short is a case of trial and error. Just take your time, work through it methodically and you will find it .

Good luck and let us know how you go.

[Big rob]

Thanks Brad, i havent tried removing the dimmer switch yet. Guess i better look at how to remove the dash. What else can i do besides wasting fuses(dont have any spares right this minute) to see if its not shorting/shorting?