# Any short cuts (?) for finding a dead short?



## Myrod (Dec 10, 2014)

Hi, 2015 Toyota Highlander, have a *dead short ON ALL interior lights*, everything else seems to be working. I know what fuse (10 amp) it is, because it blows a new fuse instantly when it makes contact.
I do have a diagram of the interior lighting, and the interior lighting wires but it might be a "devil" to follow them. 



How would you trace it, what would you do first? Thanks!


----------



## MTN REMODEL LLC (Sep 11, 2010)

Oh Boy.....Tracing wiring in a car is one tough deal....

The only suggestion I might have is to look over all visible wiring bunched cables looking for any wear/abrasion.

I'm interested if anyone knows any secret to chasing that down in a car.


----------



## Missouri Bound (Apr 9, 2011)

There are "short circuit testers" that attach in place of the fuse.
They have a wand that you use to go over the wiring. I imagine that this may be tedious but testers of this type are the key to troubleshooting.


----------



## MTN REMODEL LLC (Sep 11, 2010)

Missouri Bound said:


> There are "short circuit testers" that attach in place of the fuse.
> They have a wand that you use to go over the wiring. I imagine that this may be tedious but testers of this type are the key to troubleshooting.


Sort of a fox/hound for 12 volt...????

Where would you find one.... I just tried google...no results...but I'm just curious.


----------



## Missouri Bound (Apr 9, 2011)

Ww used to call them tic tracers when finding phone circuits.
But the circuit has to be de-energized before using. Harbor Freight sells some of the 12v testers and I have found a few on Ebay. I would think any automotive shop would sell them.
I have seen them that actually replace the fuse and you go from there.
I'll keep looking until I can verify a source.


----------



## Missouri Bound (Apr 9, 2011)

Tool Aid SG 25100 Short Tester
I found this on Amazon for $36.


----------



## ron45 (Feb 25, 2014)

It may sound silly to keep referring to the old days, but I think the tree mechanics was really on to something.
Whenever something wacky was going on with the lights/head lights we would look at the dimmer switch. Usually the switch was rusted and the ground point was no longer any good and replacing the switch took care of the problem. Back then the switch was located on the floor board. Now-a-days the dimmer switch is located in the turn signal but the concept is still the same. 
Sometimes when the problem is found and fixed the fuse may still blow because where the fuse goes is now bad/burnt and causing the fuse to blow.











I think Scotty goes over just about all

https://www.youtube.com/results?search_query=tracing+a+short+scotty+kilmer


----------



## ron45 (Feb 25, 2014)




----------



## Bud9051 (Nov 11, 2015)

Also check all of the lamps on that circuit. I have had a lamp go bad and short.

Try to find a mid point on the wiring where you can break the circuit and see if the fault goes away or stays, divide and conquer.

If you have an ohm meter you may be able to use that instead of burning through fuses. May want to disconnect the negative on the battery.

Bud


----------



## Myrod (Dec 10, 2014)

Just now "checking back into my question" and remembered that I neglected to mention that we had some "field mice" in the vehicle and I feel they may have eaten into one (or some) of the insulated wires. They are no longer in the vehicle thanks to the "old fashion" mouse trap. Thanks for all the responses and I will see what you suggest. Thanks


----------



## Myrod (Dec 10, 2014)

Bud9051, never thought of that, I'll check that out for continuity (If I can). I had bought a devise to replace the fuse which shuts down, instead of blowing, like a fuse but haven't tried it yet. I appreciate ALL the suggestion you guys are offering.


----------



## Bud9051 (Nov 11, 2015)

Mice is a high probability, little buggers have the chew to keep their teeth from getting too long. But their damage is likely to be visible somewhere, hopefully.

But breaking the feed wire and testing is a way of narrowing down the source of the short.

Good luck
Bud


----------



## Bondo (Dec 8, 2007)

Bud9051 said:


> *Mice is a high probability, little buggers have the chew to keep their teeth from getting too long. But their damage is likely to be visible somewhere, hopefully.*
> 
> But breaking the feed wire and testing is a way of narrowing down the source of the short.
> 
> ...


Ayuh,..... I _Agree_,..... No doubt caused by the mice,......

Follow their turds to their dinner table to find yer short,.....

The ******* way to find a dead short is to put solid copper wire where the fuse goes, hook up the battery, 'n watch for _Smoke_,......
That's where the short is,..... :wink2: :biggrin2:


----------



## Myrod (Dec 10, 2014)

Ok,,,,,,,,Decided to use the short tester instead of the meter. This is what I'm planning. Will this work? Hook a piece of copper wire, long enough to reach the back end of the Highlander, to the negative side of the tester (screwdriver type with the light in the handle). Unhook the ground on the battery, and connect the long wire to the Neg post. Put the fuse back in place, then disconnect the wiring plug at each interior light, and check the hot wire for voltage at the plug. 



Will this work,,,,,,,,,or will I "see the smoke"?


----------



## Myrod (Dec 10, 2014)

Well, I thought I'd let you guys know that I found my "shorted wire", it is one going to the light on the right side panel in the luggage area. *Now, the next thing will be following that wire to see where it comes from.*:smile: I think I am going to have to remove the right inside panel to get to it. 



Oh,,,,,,,,,,,,,,I used "ron45's" suggestion and used the "short tester" that looks like a screwdriver with a light in the handle. Thank you all very much.


----------



## Missouri Bound (Apr 9, 2011)

:vs_clap: You are halfway there.


----------



## ajaye (May 19, 2019)

has anything changed recently ?

pull ALL the bulbs and check the circuit diagram to see what else is on the interior light circuit and see if you can disconnect them all, put one bulb in at a time or one device, I'd try that



Myrod said:


> Hi, 2015 Toyota Highlander, have a *dead short ON ALL interior lights*, everything else seems to be working. I know what fuse (10 amp) it is, because it blows a new fuse instantly when it makes contact.
> I do have a diagram of the interior lighting, and the interior lighting wires but it might be a "devil" to follow them.
> 
> 
> ...


----------

