Community Forums

AirZone · 05-02-2014, 06:13 PM

My question is, why is the breakaway cable so long. If the trailer breaks away from the tow vehicle and falls on the safety chains, the cable won't pull out the brake switch to activate the trailer brakes. If you shorten the cable to much then you can activate the breaks if you make a sharp turn. How do you know what is the right cable length?

AirZone

SmokeyWren · 05-02-2014, 06:34 PM

You want the breakaway switch to lock the trailer brakes only after the trailer has broken the safety chains and is no longer connected to the tow vehicle (TV).

So the breakaway cable should be a bit longer than the safety chains. If the trailer gets off the ball but is still restrained by the chains, then you're still okay. Stop and repair as necessary. But if the trailer gets completely disconnected from the TV, then you want the trailer brakes to lockup and stop the trailer before it can run over someone and mash them into a greasy spot.

Most TTs use the house battery to power the trailer brakes if the breakaway switch is pulled. So that's usually a safe setup. But cargo and horse trailers and some other trailers don't have a "house" battery, so they have a tiny 12-volt battery on the tongue of the trailer that's used only to power the breakaway switch. That small battery needs to be checked to be sure it's still good before you hit the road each time. If you pull the breakaway switch out of the connection and the electric brakes don't lock up, you've got some maintenance to do before you hit the road.

BigBill3111 · 05-02-2014, 07:22 PM

I try to keep mine up with loose zip ties. I have a friend that had some kind of limb or road debris catch on his cable as he went down the road. Locked up one wheel completely and ground the tire down to the steel belts, before he realized it. I guess if the brakes had been adjusted properly, all tire would have locked up and then he would have realized he was pulling dead weight and would have stopped.

Cat · 05-02-2014, 10:42 PM

I understand the logic stated, but why wouldn't you want your breakaway brake to apply while your safety chains are still attached? If you are towing a car or truck and it did come loose and you tried to slow down the tow vehicle would slam into the rear of the vehicle doing the towing. Wouldn't it be better to have the brakes come on the towed vehicle so you would know its loose because it would yank on the safety chain/cable, then when you slowed the vehicle doing the towing the tow vehicle would not ram the back of the towing vehicle. And it would stay behind you because of the safety chains?

Im jumping in and asking too because I've wondered the same thing.

Scarab0088 · 05-02-2014, 10:59 PM

Like Smokey said, If the trailer is still on the safety chains, then the regular brake controller should apply the brakes normally while you stop.

The breakaway system is only for a breakaway or runaway. It should lock the brakes and would not be the best system for a controlled stop of TV and trailer.

Safe travels