Power source to toad

[CHS]

I am in the process of setting up my new Ford Ranger for 4 wheel towing.
Yes, More than likely I do not need it, but I just want to be safe.

I am at this point wanting to add a 12v charge line to the toad vehicle.
My question is, What is the difference of utilizing the OEM power source already wired in by Thor/Ford from the cab battery to the 7 way or should I re-route it using the house batteries. This is the way E-Trailers video recommends to do it.
Is there some sort of regulator that the cab uses to charge the house batteries while driving and that is why they instruct to use a line off the house batteries instead of the cab?

I purchased the 15 amp auto resetting breaker and waiting on the Demco 12v charge line kit that includes the wire, connectors, fuse holder and diode (main reason I bought it is for the diode)

[Chateau_Nomad]

I did my own toad setup including Invisibrake, brake light diodes, etc. I simply powered the Invisibrake using the 12 volts supplied by the host motorhome through pin #4 on the 7-pin connector. The 7 pin connector has all necessary power for a trailer... it's the same principle for a toad vehicle. If wired properly, the toad receives all necessary power through that 7-pin connector. The toad battery should also receive a trickle charge from that 12 volt supply.

I've never had an issue with the toad battery running down. It's a matter of doing the wiring correctly.

[DavidEM]

Well, the answer depends on what you are trying to do and how your MH is equipped.

If you are just trying to keep the Toad's batteries charged up while towing and charge them from the chassis alternator's output, then use the existing circuit from the chassis to the 7 pin connector, pin #4. That circuit is protected by a 30A fuse typically in the Ford fuse box. So no need for another circuit breaker.

But if your Toad's batteries are discharged for some reason and you have a separate charging source for your house batteries (separate from the chassis output) like solar or running your generator, then you can probably get more amps from a dedicated circuit from the house batteries to Pin #4 of the connector. But I would also put a 30 fuse to protect the Toad's wiring and use #10 wire.

But realize that you will only benefit from this if you have significant solar or you are running the generator which will power the converter.

So in general, stick with the factory pin #4 circuit.

David

[Pete'sMH]

I also just use the factory connection on pin 4. My new towed requires its battery be disconnected when towing but my braking system remains connected to the car’s battery and while I doubt that it’ll run the battery down I too elected to use the Demco charge kit. It’s a fun project.

[CHS]

Thanks All.
I was able to pull up the electrical battery schematic and found the only device is an Isolator Solenoid between the Chassis battery and the house batteries. That said I am going with the OEM pin #4 to the 7 pin connector and attach it with the Demco kit I bought for the Ranger. At least I will have the diode to protect whatever.