Blown tail light fuse when connecting trailer
 

I am new to this site and want to say hi to all reading this. I have a 2000 4R Limited with a factory towing package. I recently bought a used 6x12 U.S. Cargo enclosed trailer. When I connect the trailer lights they initially work but after a few minutes the 4R tail light fuse blows and all trailer lights go off. The trailer has a lot of lights: a row across the top front, a row across the top rear, front and rear side marker lights, front and rear lights on each fender, 4 tail/turn/brake lights, and 2 interior lights. Initially I thought I had a short but now I think maybe the trailer is simply pulling too much power for the 10 amp fuse to handle. As I mentioned, the fuse does not blow immediately; it takes a few minutes. However, if I connect the lights and then turn on the interior lights the fuse will blow immediately. Out of curiosity, I replaced the 10 amp fuse with a 15 amp fuse, connected the lights and turned on the interior lights. The 15 amp fuse did not blow. The fuse box shows the tail light fuse to be 10 amp. What are the potential problems if I use a 15 amp fuse instead? Is there another solution? Does anyone have any thoughts or suggestions? Help will be much appreciated.

Using a higher amp fuse usually will cause more problems. The fuse is meant to be the weak link. You are making it stronger which means something else has to give.

You may end up burning a wire and then have to figure out where it burned.

You could try replacing some of the lights on the trailer with LED's which draw much less power and see if that helps.

edit: I found on another forum a guy who says he has been using a 15 amp for a while with no problems so maybe you'll be okay with what you have.

Thanks Kball. According to a chart I looked at on-line, the lights on my trailer add up to approximately a 20 amp load. By going to LED I can reduce that to approximately 6.5 amps. That is probably the way I will go unless someone comes up with a cheaper alternative.

ya those L.E.D.s will work great if you can afford them you really only have one or possibly two circuit that are over loaded the running/tail light circuit and the cargo/dome circuit and they may be combined into one circuit if your interior lights on the trailer only come on when the 4runners lights are on they are. The easiest and cheapest fix would be to run a larger gage wire with it's own fuse or better yet a circuit breaker to a 30amp relay in the rear inside panel of the runner then splice into the runner's taillight circuit to activate the relay and wire it out to the trailer running lights. and or the dome/ interior lights Adding a larger fuse to the existing circuit is a bad idea toyota designed that circuit around the requirments of that veh and nothing else so be safe and add a circuit for the trailer as far as turn signals and brake lights your only adding 2 bulbs at the most and that shouldn't be an issue but going with just turn and brake/tail L.E.Ds will be cheaper than replacing all of the lights. The L.E.D.s would still be the best choise but man are they expensive I saw an L.E.D. site online that had replacement bulbs but most trailers come with sealed lights by Grote or such which means buying their lights at $35 to $70 a piece last time I looked. good luck buddy

Thanks for the input. I replaced the lights with LEDs. They were expensive but work great. No more problem.