2000 Sienna - Tail Light/Parking Light Keeps Blowing Fuse

[tkjaubert]

Hi,
We own a 2000 Sienna XLE. It showed to be in service at mutliple Toyota dealers for electrical during manufacturer warranty. (we bought it used) We had experience minor electrical gliitches over the years but nothing like this.
Problem:
I have no tail light or parking lights on the rear hatch. The brake lights and reverse light DO work, just no tail/parking lights. Every fuse (10,20,30) blows as soon as i switch the head lights on. I have disconnected the harness on the back hatch that leads to the tail lights and the fuse still blew. This leads me to beleive that the short is closer to the fuse box.
Has anyone dealt with this or has any suggetion in the best way to diagnose this problem without tearing apart our family vehicle?
**I have checked all of the double filament bulbs and all are working fine**
Very much appreciated!

[Black Sunshine]

Do you have an aftermarket radio? If so you need to take it out and check the wiring. If the illumination wire isn't hooked up and shorts out it will blow whatever fuse it's on. Whenever there is an electrical problem check things that have been messed around with in the past.

Does it have a trailer hitch with the plugs for lights? If so check that wiring. You definitely have a short there somewhere.

[tkjaubert]

I do have an aftermarket tv installed on the same harness/set up as the oem tv. I have check all of the funstions on the television and all are working fine.

I guess you are saying there could be a wire that was left unhooked that is now touching a ground, etc.?

What about the double filament bulbs on the front? Is it true that if they are touching then it will blow a fuse?

[wiswind]

Anything "aftermarket" that was added after the vehicle left the factory needs to be checked out.
Not just the plug, but where the wires from the plug are spliced into the vehicle wiring.
THIS is where sloppy work is very common.
This will be behind the trim, etc.
For this reason, I would try to think of everything that may have been added to the vehicle......the TV, aftermarket radio, wiring harness for towing and aftermarket alarms / remote starters are all common add ons that can cause problems.
Again, it is where they splice into the factory wiring that you need to be looking.
Any unconnected wires that are left to bump into things, or splices that are not covered with something that keeps the metal part of the wiring covered.

[Black Sunshine]

A light bulb itself causing a short does not seem likely. If you're really worried about it take the bulbs out and see what happens.

I don't know about an OEM TV but mine had an aftermarket TV installed before I bought it and it was spliced into the radio harness. The splice job totally sucked so when I replaced the aftermarket TV with another I cleaned it all up.

Like Wis said check out all of the splice connections for the aftermarket things. This is the first place to look.

[tkjaubert]

Best Buy did the install. The guy that did it had been there for about 5 years. While we are on topic, ALWAYS interview your install guy before anything aftermarket goes in your vehicle. I have seen a LOT of remote start stories regarding tail lights though.
Thanks for the insight.

[tkjaubert]

Ok. I have found the solution and fixed the problem!

Thanks to everyone that had responded to my post. This is another great display of "people helping people".

DIAGNOSTICS: I unplugged the harnesses on the rear lift-gate, installed a new fuse, and the fuse still blew. At this point the short had to be before this and most likely in the front. (double filament bulbs will not blow your fuse by the way)
The Chilton book shows where all of the grounds for your electrical are and that is an excellent place to start. (i'm sure they can be found online as well)

PROBLEM FOUND: There was a short that had melted the wires together and exposed naked wires within the group/bundle/etc. I found this nearest a ground (paint ground) near the front left suspension pillar. This is where a vital ground for the tail lights is located on first gen Siennas

CAUSE: A bad ground caused a short on the wiring and I assume overheating (probably the 30 amp fuse i used...on a 10 amp breaker during my diagnosis, actually cooked them!) None the less, my wife had a minor front left fender bender and teh bolt had a bad ground point on the body. Over time i guess it got worse.

FIX: I replaced the bad wires (don't just twist them people, use connectors, they are cheap) and unscrewd and rescrewed the grounds making sure there was a good clean connection and tested the fuse. THANK GOD it worked on the first ground I tried.......the one nearest the cooked wires, duh.

LESSON LEARNED: Body damage will cause bad grounds, Even though a vehicle has been cosmetically repaired the slightest bend or tweak can cause a poor connection. ALWAYS check your "paint grounds" (ground points). Although bad grounds don't cause fuses to blow, they do cause shorts and shorts can be VERY hard to find sometimes. GOOD LUCK!

[Black Sunshine]

I hope I mentioned this before. To check ground points if you had an accident, that is.

I had the front end of my previous vehicle rebuilt after hitting a deer at 60mph. The body shop didn't re-install the ground straps properly. In my case it caused the ECM to go nuts and throw all kinds of codes. In my case I couldn't figure out the problem, it was right after I got it from the body shop, so I just took it to the dealer. They charger me about $300 to fix it. I sent the bill to the insurance company and they sent me a check right out.

I was really disappointed with the quality of body work that was done on my vehicle and this was icing on the cake. If they remove ground points, paint, then re-install the grounds they should sand the surface well. It's simple, yet it doesn't always happen.

In your case you found that a poor connection can generate heat. This is a simple electronic principle. When the wire(or connection/connector) isn't large enough for the load it heats up. This happens in bad connections because there isn't enough contact surface. I experienced the melting wires problem on a car that had problems with fusible links. Luckily they don't use those anymore.

[jrtheflash]

Hi there, i don't know where or what is a suspension pillar. could you elaborate more. its on a 2000 toyota sienna. the problem is when i put a bulb in the front 2 sockets the fuse gets blown out. narrowing it down but still could use the info. thanks for your time Jr.

[chuck's sienna]

I recall reading that the number one cause of vehicle fires is..........bad wiring and poor grounds after an accident repair!

[SiennaCruza]

Could improperly ground wires cause the Alarm to trip from time to time? I've yet to check the hood and door switches but I wish I had more technical knowledge of the electrical system and ground points of my 99 sienna that had a couple fender benders. Left fender damage and right sliding door are just some of the issues that have been properly repaired but make me think. Thank You

[jrtheflash]

Hello, hows it going, thanks for the info about the painted ground. i just don't know where that would be. could you give me some more input on that so i could find it please. i just thought i fixed it with bulbs but it came back. thanks for your time Jr.

[jrtheflash]

Hi all, how's it go? i'm looking to see where the painted grounds are in my toyota sienna. can anyone point me in the right direction. this guy said its by the suspension pillar wherever that is. he had a short near there. the guy is tkjaubert. he might be at the end of this thread. his title is, ok i have found the solution and fixed the problem. i need your assistance, please reply. thanks Jr.