2003 Tacoma 4WD—camper turn signal lights don't work. Any ideas?

I have a 2003 Tacoma. I hooked my camper trailer up and its turn signals don't work, although the brake, running lights and regular lights do. The Goodyear store where I take my truck for servicing told me it's likely a blown fuse in the truck. I checked all the 7.5-20 fuses in the fuse box under the hood and in the dash, and all are okay. Is there some other fuse box I don't know about? Any other ideas to fix it?

 

Did your truck come with a factory tow package? If so, look behind the drivers side back seat. Look for a black box mounted to the cab wall. The wires going into the box have inline fuses. Check those.

 

Thanks for the advice, and yes, I do have the factory tow package. I'd also seen elsewhere in the 2004 Tacomas to check behind the driver's side back seat. But on my 2003 model nothing is anywhere behind the rear seat—just the jack. I pulled back the carpet to the back of the cab and looked, and nothing there either.

 

You may have to trace the wires from the plug towards the the front of the truck looking for where they go through the cab. I have a Dbl cab and my trailer light control box is behind the drivers side back seat.

 

Thanks for the suggestion. I just now finished tracing the wires from the back. As near as I can tell, unless there's some other wires that branch off that I can't see, they enter the cab underneath the driver's seat. That whole area is carpeted with no access except where a slender air vent comes out from under the carpet. There's no way to access the wiring from there without removing the driver's seat and carpet.

 

Hmm. Ok I can remember that the bulbs on the trailer have 2 elements. One for the running lights and the brake lights and the other for the signals.
See if the hazard lights work. It may be a relay. I don't have a wiring schematic available to verify that.
I have seen pictures of some U-Haul setups with a control box behind the driverside tail light on the truck. From my understanding, all factory installed trailer packages had the black box behind the back seat on the driver side.
Grab a multimeter and verify that the truck plug on the bumper is in fact working or not and not a trailer wiring issue. The turn signal wire should show intermittent voltage with each signal flash. I have been in your shoes, found that the trailer wiring was shorted out after combing over the truck looking for the issue.

 

Thanks, and yes, the hazard, brake and regular lights work. Only the turn signals don't (both sides). With a meter I was able to establish that the pins (if that's what they are called) in the plug on the truck work for the lights. The top two pins worked, but not the others.

I did find the converter box behind the driver's side tail light, but couldn't find any inline fuses there or to the plug or before the wires all went into the writing tube going toward the cab. The wires are all enclosed in the tube from there to the cab.

 

Help me understand. The hazards DO work on the trailer?

 

Yes. Hazards work, brake lights work, running lights work and the regular lights work. Only the turn signals don't work.

 

This has me puzzled. With a multimeter, check the wires going into the control box. I am running out of ideas of what it might be. Do you have a Haynes manual for your truck? It may be time to look at the wiring schematic.

 

Thanks, I'll try that next. However, it will have to wait a week because I have to pack and leave for a business trip that will take me away for the next week.

I don't have the Haynes manual, but may have to invest in one.

Thanks very much of your help!

 

Your welcome Scott. I hope you get it figured out. I will keep racking my brain.

 

The converter box needs to be a five wire to four wire stepdown that is designed for vehicles that have separate wires for turn signals and tail lights. Hopkins make one for around $25. Problem sounds to me like a four wire converter is installed. Just a thought.