Break away switch pulled

[royorbison]

Anyone have experience with break away switch pin pulled with power on for extended time, could there be any kind of damage to the brake system. found pin laying on ground in driveway battery. Was in on position. I reinserted pin ok, but worried about braking.

[cboss]

I think the brakes will be fine. The batteries are a different story.
How long was "extended time"?

[KyDan]

I donno.... brakes full on at 12v until battery dies? Brake coils could have been over heated. Can't say your ok or not. A brake test is in order. Maybe others with actual experience can give their opinion.

[royorbison]

Maybe days but trailer was also plugged into 30 amp shore power at house

[cboss]

Originally Posted by royorbison

Maybe days but trailer was also plugged into 30 amp shore power at house

In that case I think the batteries will be fine.
I would think that the brake magnetics would be fine, but like above a brake test is in order.

[A32Deuce]

I think I would pull a wheel to see if OK or pull all wheels to check. Good excuse to doo wheel bearings.

[KyDan]

Hitch up and apply trailer brakes and give it a pull. See what happens. Remember electric brakes only work in forward direction. Much less in reverse.

[Bama Rambler]

I'd be more worried about burning up the switch contacts than most anything else. ±12 amps running through those switch contacts for a few days isn't going to be good for them.

Inspect that switch while you're inspecting everything else.

[wildcatter]

Originally Posted by Bama Rambler

I'd be more worried about burning up the switch contacts than most anything else. ±12 amps running through those switch contacts for a few days isn't going to be good for them.

Inspect that switch while you're inspecting everything else.

It is 12 Volts not 12 amps.

[cboss]

You can test that switch by jacking a wheel, spin it, then pull the breakaway.

[TitanMike]

Originally Posted by wildcatter

It is 12 Volts not 12 amps.

If the trailer has tandem axles with four brake magnets, 12 amps is the lowest average current. Mine draws just over 14 amps when switch pulled.

Yes, 12 volts going in but don't forget the current part which causes the heat.


That said I'd wager that the breakaway switch is rated between 20 and 30 amps as some trailers have three axles and 6 magnets drawing 3-4 amps each.

[TitanMike]

Originally Posted by KyDan

I donno.... brakes full on at 12v until battery dies? Brake coils could have been over heated. Can't say your ok or not. A brake test is in order. Maybe others with actual experience can give their opinion.

Perhaps however two things in their favor. First, they're designed to work in a hot environment to begin with. Second, if activated they're attached firmly to the brake drum which is now a huge heat sink.

As was mentioned earlier, the weak link would be the switch.

[wildcatter]

Originally Posted by TitanMike

If the trailer has tandem axles with four brake magnets, 12 amps is the lowest average current. Mine draws just over 14 amps when switch pulled.

Yes, 12 volts going in but don't forget the current part which causes the heat.


That said I'd wager that the breakaway switch is rated between 20 and 30 amps as some trailers have three axles and 6 magnets drawing 3-4 amps each.

I stand corrected, I did not realize they pull that much current. See you can teach old dogs new tricks.

[Bama Rambler]

Originally Posted by wildcatter

It is 12 Volts not 12 amps.

It is 12 volts, but if you do the math it's ~ 4Ω per magnet divided by 4 magnets = 1Ω, and 12 volts x 1Ω = ~12 amps. More or less.

Mike's right about those switches being rated for 20 amps, but given the location of most of them, the weather beats them pretty hard, so they're not in the best of shape after a little while.

[TitanMike]

Originally Posted by wildcatter

I stand corrected, I did not realize they pull that much current. See you can teach old dogs new tricks.

It's all good

[wildcatter]

Originally Posted by Bama Rambler

It is 12 volts, but if you do the math it's ~ 4Ω per magnet divided by 4 magnets = 1Ω, and 12 volts x 1Ω = ~12 amps. More or less.

Mike's right about those switches being rated for 20 amps, but given the location of most of them, the weather beats them pretty hard, so they're not in the best of shape after a little while.

I know, I already responded to Mike.

[wmtire]

Originally Posted by cboss

You can test that switch by jacking a wheel, spin it, then pull the breakaway.

Just to clarify, you do not want your RV connected via the umbilical cord to your tow vehicle when you test this. Some proportional brake controllers specifically state to not do such as the backfeed from your RV's battery to the controller in the tow vehicle can damage it.

We have several threads on this.

[cboss]

Originally Posted by wmtire

Just to clarify, you do not want your RV connected via the umbilical cord to your tow vehicle when you test this. Some proportional brake controllers specifically state to not do such as the backfeed from your RV's battery to the controller in the tow vehicle can damage it.

We have several threads on this.

Thanks for the info. I learn something everyday from this forum.

[Tundra 2014]

Pulling 12 amps on a 105 Amp battery, a day, battery is pretty much dead. I caught mine accidentally when unhooking at storage. When I went back 3 days later, realized the error. I had to replace battery as it would not take a charge. This was on a 1 year old Group 31 battery. When I did my next trip, we did a brake test- no damage. Also checked w/ wheel spin test when I had wheel up lubing bearings. Check battery and test brakes.

[wmtire]

Originally Posted by cboss

Thanks for the info. I learn something everyday from this forum.

You are very welcome. Screenshot from the popular Tekonsha Voyager brake controller owners manual. #3 explains it.