Any Toyota Techs Here?

Two local service departments can’t answer the question. Toyota Corporate can’t answer it. I tow a little T@b trailer. My 2019 Tacoma doesn’t supply enough amps through the factory 7way plug to charge my trailer battery. I get a warm refrigerator after a days towing. So I want to run a independent “hot” wire from truck battery to 7way. I wired, not through truck, but directly, my 1st gen for trailering. Always worked fine.
Question: Will bypassing factory trailering harness with one hot wire spliced into 7way screw up truck electronics?
Thanks

 

Run the new wire with a fuse by the battery back to a relay (use waterproof relay) behind the rear bumper. Use the factory tow aux power circuit to run the control side of the relay and run the power from the relay back to the factory outlet. This will allow you to keep the single plug to the trailer and keep the truck only providing power to the trailer when it is on. Shouldnt cause any issues with OE sytems. Just remember, fuse, waterproof relay, solder is better than crimp, marine heat shrink any connections that arent in a housing.
Note- I am NOT a Toyota tech or engineer. This is just what I would do on my vehicle.

 

Dealer nor Toyota should answer that question as it's not a factory OEM question. Good luck and I'm sure somebody here can answer.

 

I dont think it will cause any issues as long as the +12v pin in the plug is always hot on 3rd gen trucks. If the +12v hot pin is switched on the key (if the key needs to be on to provide +12v at the plug) then there might be some weird stuff with the always-on back-feeding the truck. If that makes sense..

If you do decide to run a dedicated wire, make sure you use proper fusing / circuit breakers as close to each battery as possible. Make sure you size the wire properly to account for the max current the trailer could potentially draw. And lastly, take the length and size of the cable into account for calculating the voltage drop under that max load.

All that being said, Im not sure this is your problem.. Seems like if you didnt blow a fuse somewhere in the truck, then the truck can in fact supply enough power to the trailer. Are you sure its not your fridge? Is it vented properly? Is it purely electric, or is there a propane option (are the settings for that option..)?

 

After re-reading your question, my first point wont matter if you intend to completely disconnect the factory hot pin from the plug and replace it with your own wire. But again remember that the factory plug is probably only technically rated for as much current as the stock fuse will allow. If you decide you actually need more power, you may want to look into a dedicated weather-proof connector for the 12v circuit that you can route near the factory 7-pin

 

Without some measurements, it's hard to say whether running a new wire would fix it. I'd be really curious to see what the voltage is at the truck battery, trailer plug and trailer battery with the truck running and everything connected.

 

It was when I started the troubleshooting adventure and hit up dealer service department. I started by inquiring what amps were supplied at the 7way because my battery was going dead. But my 1st gen worked fine. The service manager did spend some time on the pad looking for the answer. Didn’t find it and referred me to Corporate. They answered, don’t know and said dealer service would know. So I next hit them with the above question.

 

That resembles my 1st gen setup. But we know those trucks are much less “tron” loaded.