Wiring 7-way & brake controller to tv battery

[Triker]

In the drawing below, is it best to run the 20A circuit breaker '???' post direct to the vehicle battery? Or is it okay to jumper it to the 'wire to battery' post on the 30A circuit breaker?



I can easily wire it either way, the battery is approx. 12" from the circuit breaker. It would just be a little bit cleaner install with less wire, BUT I don't know if there is a 'negative' side to doing this.

I ran 8 gauge from the 7-way connector, and 10 gauge from the P2 under the dash.

Thank you!

[cmartin748]

If it only wants 20 amps, only give it 20 amps. If you run it from a breaker that has nothing else on it, put an inline 20 amp fuse on it.

[Wayne Collins]

Get it to a reliable trailer shop.

On ours, I think, there are two heavy gauge wires connected to the battery "+" post, each with an in-line 20amp fuse. One wire runs all the way to the 7 pin connector. The other goes through the firewall to the brake controller, with a connection to the brake light switch - that triggers the trailer brakes; via the second wire to the 7 pin. Depending on how well your TV frame is grounded, you may also need a separate ground wire from the battery "-" post to the 7 pin.

[Triker]

Conclusion: I ran a separate 8-gauge wire from each of the circuit breakers to the vehicle battery.

After talking with others at the Spring NOG last weekend, this is the way it should be done - NO jumper; wire each circuit breaker direct to the vehicle battery. (Thanks, Art!)

[Terry M]

Go to e-trailer.com and watch one of their vehicle specific videos. I used their universal 7-pin wiring harness and used their supplied 30 amp breaker to the controller and the 40 amp breaker for the battery charging circuit. No jumper, two separate wires to the TV battery.

[CarlD]

Guidance on making a decision: Circuit protection devices are designed to protect the wires not the load. Loads usually have their own protection mechanism. i.e. Some motors say 'impedance protected', some loads specify a max fuse size.

If you run a wire from the battery to some fuses for distribution to loads, you need to make sure the wire is large enough to handle the maximum load from all circuits. In other words, if you have a 20 fuse and a 30 amp fuse, the maximum load on the wire is 50 amps. There are exceptions to this rule, however this is for general wiring. That being said, it is best to have the fuses connected individually to the power source (battery). You can have a short piece of wire connecting the battery to the fuse but make it as short as possible and large enough to handle the maximum current the fuse will allow.