Hidden fuse for trailer lights?

I have a 2008 TRD V6 with according to my VIN a factory tow package. It has 7 pin connector and has 12V at trailer plug with key on through the black wire and power to running lights with headlights on but that is all, no brake or turn signals. I have been searching and it is suggested there may be other fuses somewhere. Anyone know where they may be?

 

Did you check the in cab fuse box? My 3rd gen has the main fuse box in the engine bay and there is a secondary fuse box under the dash on the driver’s side.

 

Should be a fuse box behind the little cubby thing to the left of the steering wheel (above the hood release). In addition to the main fuse box in the engine bay, drivers side. Google should help you figure out the rest.

If you find all fuses to be good, you might also check the trailer wiring harness itself. Certainly possible a few wires have frayed and snapped off from the plug after 11 years.

 

I checked both fuse boxes, hear tales of fuses in jack box under rear jump seat didnt find anything there either

 

A few simple google searches should be able to tell you exactly what fuses you need to be looking at, based on your exact symptoms. (Test the fuse with a multimeter for almost zero resistance between the pins, in addition to just a visual check)

From there you can move onto looking at other issues like broken wires.

 

Been searching google for hours. Since it is a factory installed option they dont show up on the wiring diagrams

 

Also cannot locate the towing converter relay

 

https://www.autogenius.info/toyota-tacoma-2005-2008-fuse-box-diagram/

Looks like you have several fuses to trouble shoot

 

nothing wrong with those fuses

 

Check the "Towing relay" fuse in the engine bay. And check the towing converter relay in the drivers kick panel area.

 

What are you using to check the power at the connected, if you've got a trailer hooked up and are watching those lights I would not suggest that. Get one of

$12 CURT 58270 7-Pin RV Blade Trailer Wiring Towing Vehicle Socket Tester, Black

these or something similar so you are only looking at the truck and nothing else. At my dealer we get an annoying amount of "well I have this problem when my trailers hooked up" but people don't bring the trailer and the trucks test 99% fine.
Haynes manuel doesnt have trailer lighting diagrams, I can check in Alldata tomorrow and see what they have for trailer lights.
Not to be mean but how good are you with electrical testing/knowledge?

 

Im not an electric guru by any means but have at least average troubleshooting knowledge. I am not using trailer lights but a test light and multimeter. I do know for sure that there is power from the black wire 12V with key on and power from the green tail light wire. White ground wire also tests good. Same thing on the "other" side of the BE1 towing harness connector. From what I can tell I would have to pull the whole dash out of the truck to get to the towing converter relay are there issues with the longevity of those relays? Amybe the relay is easier to get to than I think? In order to tow my friends boat this past weekend I opted to splice in a generic flat 4 connector to the tail lights. I don't need trailer brakes and all of that but it would be nice to not have two trailer plugs at the hitch, one not working. Any help is appreciated.

 

Have you done the simple first??

Pull the plug apart check for broken or wires pulled out.

If you live any place winter chemicals are used corrosion might be a problem.

Installing Hitches and connecting plugs for years fixing things every spring is a given

 

Testing by probing wires ahead of the connectors to rule them out.

 

Here is what I have from Alldata, its not much since the diagrams done tell you which fuse is where in the fusebox but I hope it will help. I also have a 08 with towing so if you are not sure something is in the right place I can check mine assuming its easy to get to.
Dont think this would matter since you are talking about the four pins connectors but do you have a trailer brake controller installed, without that a few pins on the 7 pin connector wont ever have power at the trailer plug.

I have had to deal with a few older fords that I wasnt sure which fuse was which so I just took a voltmeter, hooked one end to ground and touched both sides of every single fuse to see if it had 12V, if both sides have 12V then the fuse is good.