Damaged hitch relay board

[Joe Camper]

No it is protected with circuit breakers and spade fuses. I'll email u a picture of the schematics for all 379 model peterbilt that was about a 15 yr run so more than a few. Mac KW Freightliner all of them r void of this converter added board of protection we r discussing.

I quite electrcly ignorant so I'm still trying to wrap my brain around isolate power source from dedicated power.

What protection does that board and relays provide that a circuit breaker and possibly a diod would not?

Please enlighten me yoda sparky.

[Joe Camper]

IMG_20211224_093945189.jpg

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The firewall side where it says trailer that's my 7 wire to the trailer going into that loom protector.

This is the American version of protection for comparison and discussion.

This is the front and back of peterbilt fuse panel. Only 3 relays total. They separated the headlights and relayed those and the horn. PERIOD. Even the power for the marker lights, trailer included run right through the switch on the dash. Blower motor spade fuse and through the switch on the dash. A/C clutch spade fuse and through the switch on the dash.

0023617_be24020-7-way-receptacle-20-amp_300.jpeg

As for towed electrical protection all trailers all have a female receptical like this one that house 7 circuit breakers.

This represents decades of production.

[amt]

Well, I have moved the right-turn light to the reverse light circuit (removed the reverse signal), and I removed the electric-brake signal from my 6-wire connector, so I could have: ground, battery-charge, left-turn, right-turn, stop, & driving (tail) lights. I realize this is not standard wiring for a 6-wire connector. I have not yet tested with everything all connected, but I did test with a voltmeter at the end of the coach, and oddly enough, when one turn signal is going, I get a faint signal on the opposite turn signal, like 2-3 volts on and off. I suspect this is due to that overly-complicated mess of relays that have to combine the stop and turn signals. So I may just remove those particular relays, as I am not using the combined turn and stop right now. I plan on leaving on the 26th for a short trip, but we may just choose to not pull the toad this time.

Eventually, I will redo all of this, and I am leaning towards one of these: https://www.etrailer.com/Trailer-Wir...-S14-07-6.html
It's a little bit more expensive, but IMO far nicer than anything I have ever seen for trailer hook-ups. 14-wires can get me anything I could possibly need, and they provide adapters to standard trailer connections, in the rare case I would need that. 14 conductors allows me to have pretty much all combinations of signals and power, and it looks like the company will even build you a custom cable (should you need something like a lower gauge wire): https://cdn.shopify.com/s/files/1/03...f?v=1622573679

One other thing I plan on doing is using an actual DC battery charger for the charge wire. I do not think it's a good idea to wire the two 12v systems directly together. If one battery is low, the other may produce so much current that you are very likely to blow a fuse or trip a circuit breaker, or if you do not have those, melt a wire. I'd rather have control over the max amperage going to the toad battery. I already have the charger (Renogy, 20A, but can be set to 10A), so if I am feeling up to it, might wire that in tomorrow.

[Gil_J]

IMG_20211224_093945189.jpg

IMG_20211224_094609923.jpg

The firewall side where it says trailer that's my 7 wire to the trailer going into that loom protector.

This is the American version of protection for comparison and discussion.

This is the front and back of peterbilt fuse panel. Only 3 relays total. They separated the headlights and relayed those and the horn. PERIOD. Even the power for the marker lights, trailer included run right through the switch on the dash. Blower motor spade fuse and through the switch on the dash. A/C clutch spade fuse and through the switch on the dash.

0023617_be24020-7-way-receptacle-20-amp_300.jpeg

As for towed electrical protection all trailers all have a female receptical like this one that house 7 circuit breakers.

This represents decades of production.

Dang, 30A taillight and 35A brake lights! Oversized wire and fuses is one way to do it. That must be #8 wire.

[Gil_J]

Andrew,

The faint voltage on the turn signal is a poor ground or, as you suspect, the combining function electronics. There's no way I'd consider a non standard connector. 6 and 7 pin connectors work and if you need to replace one on the road they are easily found. If the vehicle needs seperate brake and turn lights, use a 2 to 3 converter. I've used a 3 to 2 on my coach and 2 to 3 on my Explorer for years. There's a much better choice than running a battery charger. Here's a regulated power system.
https://rvibrake.com/products/towed-...y-charger-plus

[Joe Camper]

"Oversized"????????

No those r the correct components to achieve simplicity and reliability. That's how the groceries get to the store. Void of circuit boards that create the very problems they r put in to avoid.

I do not think the loom is constructed of #8 wire Gill I will have to check.

The dash power is fed through an 80 amp relay not on that panel rather up behind the dash but that's it.