New Jack wiring with trailer breakaway switch?

[chilipepper]

So I just put a new Husky Super Brute on our 1971. I installed it with the circuit breaker provided but put the trailer breakaway switch also behind the breaker with the jack. The more I thought about it maybe I should have put the breakaway switch direct to the 12v power line and not behind the breaker. Any help or thoughts would be appreciated!

[Mollysdad]

Yeah, I'd bypass the breaker. It the switch is pulled it puts 12v. direct to the brakes, I'm not sure how many amps, but to be safe, I'd leave the breaker out of the path.

[Bobbo]

Breakaway switch should not be fused or on a breaker.

[chilipepper]

Thank you both for your reply. I did remove the breaker from the line to the breakaway switch. The entire 12v line coming from the rear of the trailer is however, fused. It was that way originally. There is a 20A fuse on that line and since the fuse panel is in the rear of the trailer and an old trailer at that, I'm a little nervous running that long of a wire unfused to the tongue of the trailer.

Any additional thoughts on that? I do sincerely appreciate the comments!

[ROBERT CROSS]

You could tap into the 12v line in the AS umbilical cord.
That goes directly to the batts in our Classic.

Bob
🇺🇸

[BayouBiker]

Yeah fuses and breakers are designed to prevent wire damage fires and worse. The idea with brake away is it's better to have the wires burn up rather than have the brakes not work. But honestly, if you are using a WD hitch, the chance of ball separation is nil.

[CBWELL]

Ball seperation is nill, BUT, shank coming out of receiver is a possibility with a WD system!! Therefore a break away is necessary. Shoud be direct line with no fuse or breaker.

[BayouBiker]

True that. The receiver pins are strong beyond limit even accounting for fabrication error. So Human error is the only reasonable possibility. weak receiver mount is the only other issue but if you hook the break away to the receiver, that won't help. Such is the nature of risk mitigation. Fool proof is a misnomer.

[dznf0g]

Originally Posted by BayouBiker

True that. The receiver pins are strong beyond limit even accounting for fabrication error. So Human error is the only reasonable possibility. weak receiver mount is the only other issue but if you hook the break away to the receiver, that won't help. Such is the nature of risk mitigation. Fool proof is a misnomer.

That's why I run my breakaway cable to the truck frame, forward of the receiver.

[KK4YZ]

Originally Posted by dznf0g

That's why I run my breakaway cable to the truck frame, forward of the receiver.

Simple connection point: replace one of your license plate bolts with a eyebolt. Connect the breakaway to that. Just make sure the eyebolt is nice & tight.

[BayouBiker]

Originally Posted by KK4YZ

Simple connection point: replace one of your license plate bolts with a eyebolt. Connect the breakaway to that. Just make sure the eyebolt is nice & tight.

On my truck that wont help, my bumper and license plate are attached to the receiver mount which really is a bolt on extension of the frame.....

If mechanical engineering were easy, we wouldn't need any....

Edit: Two years ago my wife was rear ended in the snow in Chicago. Did 12k damage to the infiniti that hit her. We had a small ding in the bumper and one of the hitch chain rings got bent. That's all.

[Bobbo]

Originally Posted by dznf0g

That's why I run my breakaway cable to the truck frame, forward of the receiver.

This is what I do too. Forward of the receiver and forward of the bumper mount.

[Bobbo]

Originally Posted by chilipepper

Thank you both for your reply. I did remove the breaker from the line to the breakaway switch. The entire 12v line coming from the rear of the trailer is however, fused. It was that way originally. There is a 20A fuse on that line and since the fuse panel is in the rear of the trailer and an old trailer at that, I'm a little nervous running that long of a wire unfused to the tongue of the trailer.

Any additional thoughts on that? I do sincerely appreciate the comments!

It is possible to fuse that long wire but bring the breakaway switch off before the fuse. The breakaway can even be wired directly to the battery.

[ROBERT CROSS]

Originally Posted by BayouBiker

On my truck that wont help, my bumper and license plate are attached to the receiver mount which really is a bolt on extension of the frame.....

If mechanical engineering were easy, we wouldn't need any....

Edit: Two years ago my wife was rear ended in the snow in Chicago. Did 12k damage to the infiniti that hit her. We had a small ding in the bumper and one of the hitch chain rings got bent. That's all.

I use the left side lift gate latch, replace the zip-tie in the photo with the cable loop.👍

Bob
🇺🇸

[chilipepper]

This is some great discussion. I can see why they decided to put the batteries in the front of the rig on newer trailers. It is a strange risk vs convenience decision. Batteries and fuse connection panel are literally the furthest you can get from the tongue of the trailer. It leaves a long length of wire to become a filament if there was a short and was unfused.

I wonder what the theoretical max amp draw on the brakes would be if the breakaway was pulled and the brakes were fully engaged under load?