Might want to take your spare tie down and check for wire problems there plus
- you can practice the process in case you have a flat tire tomorrow;
- you can check the tire air pressure, it could be surpriseingly low;
- you can rustproof the area and the back side of the rim;
- you can rustproof/lubricate the cable mechanism.

Do you have dielectric grease handy? A little dap on spark plug terminals, inside spark plug boots, light bulb connections, etc works wonders at keeping things greased and connections protected from moisture.

 

Took spare tire down. All the towing wires are good to go as far as I can see before it goes up into the chasis. I have some wiring schematics that I'll go over and try and find where the short is or bare wire.

 

I had a similar problem happen with a Chevy Venture. Different vehicle than yours, but electricity works the same. I'll share the information from that mess.

In that case, the board that held the bulbs on one side was bad. It caused the negative connection on the plug to melt. No negative connection, so the power would try to flow wherever it could, causing the back end to light up like a christmas tree whenever I used the left turn signal, or the brakes whenever the headlights were on.

Replaced the plug, it worked fine a couple of months until the new plug melted. Replaced the circuit board and the plug, worked fine for years.

 

I swapped the tail lights last night and the prpblem still exists as stated in my original post. The problem stayed the way it was. So, that tells me that my tail light(s) electronics are fine and not melted or anything. The plugs are good and making contact. So the problem with the current is before it gets to the tail lights? I have no idea what to try next. I'm just gonna have to take it to a mechanic let them figure it out at whatever cost.

 

There's leakage somewhere for sure. Some suggestions.
- when you apply the brakes, do any other rear lights come on back there, that shouldn't?
- check your relays, take them out and clean them up.
- any wires coroded around the battery area?
- I would be tempted to cut a wire or two from the trailer lights connection, test and then connect them back up.
- any body work been done on your vehicle recently that may have damaged some wires?

 

Problem soved!!! I finally had to take it to my mechaninc and it turns out that the turn signal/brake light splitter for the towing harness went bad. I would have never of found that little device. Anyway, all is good now with left hand turns. Thank you to all who responded and helped me try and reslove my problem. Thanks again and good night.

 

Was that just a plug in connector in the jack compartment?

 

Yeah, I guess so. It as behind the jack compartment panel. It was some kind of diode splitter for the tow harnesss.

 

Thanks. I'll keep that in mind.

 

I know this is years late, but thanks for the thread.

I've owned a 2000 Dodge Caravan for 10 years. It was a leased vehicle and we bought it from the dealer with 12,000 miles on it.

I had the same problem (well sort of). When I stepped on the brake the left front turn signal light came on.

My van had no towing package. There are no cables underneath, but this was the only thread that came close to my problem. So I took out the jack and found some after market cables plugged into the left rear light plug and an extension plug sticking out the van body to the left rear light assembly. Obviously the previous owner had added a towing package and removed it before returning the lease.

If I had known better, I would have realized that the white (non color coded wires to the plug at the light were after market as they didn't have the Dodge color scheme.

I removed the extension and re-attached the proper plug to my rear light assembly and the problem went away.

Thanks for the thread. Without it, I would have ripped the car apart trying to find the short.