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Topic: Emergency trailer brake wire
Posted By: brulaz on 04/14/17 05:25am

In my trailer there was the main, unfused, 6ga line leading from the batts to an electrical box with circuit breakers in the "basement". About 2-3 ft long. The line to the emergency brake switch connects to that main line before the breakers in the electrical box in the basement. And so was also unfused.

Thinking that all lines from the batt should be fused as close to the batt as possible, and forgetting about the emergency brake line, I fused that main, 6ga line right at the battery.

But now I'm thinking that the line from the batts to the emergency brake pull-out switch should not be fused, anywhere along its length.

Correct?

Or is it one of those "maybe yes, maybe no" situations?

2014 ORV Timber Ridge 240RKS,8500#,1250# tongue,44K miles
690W Rooftop + 340W Portable Solar,4 GC2s,215Ah@24V
2016 Ram 2500 4x4 RgCab CTD,2507# payload,10.8 mpgUS tow

Posted By: BFL13 on 04/14/17 07:45am

The schematic for our trailer shows the emergency brake wire (a positive) "not fused" seeming to make a point of that.

1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
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2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
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Posted By: ScottG on 04/14/17 08:08am

It's more important for that wire to stop the trailer than it is to protect the wire form an overload. In fact, if that wire has to melt to do its job then that's fine.
I have never seen that wire fused in any trailer. I would rewire it.

Posted By: SoundGuy on 04/14/17 09:23am

The breakaway switch on my Coachmen Freedom Express was wired by the factory through the resettable circuit breaker to the battery's + terminal. I guess I've exacerbated the situation by adding a battery disconnect switch, 'though because I always tow with the switch on the fact it's in the circuit is moot.

[image]

I'd agree with others though that the breakaway switch should be wired directly to the battery - no fuse, no CB, no switch, so I really need to put this wiring correction on my "to do" list for this spring. [emoticon]

2012 Silverado 1500 Crew Cab
2014 Coachmen Freedom Express 192RBS
2003 Fleetwood Yuma * 2008 K-Z Spree 240BH-LX
2007 TrailCruiser C21RBH * 2000 Fleetwood Santa Fe
1998 Jayco 10UD * 1969 Coleman CT380

Posted By: dougrainer on 04/14/17 10:27am

The Breakaway Switch is NEVER fused. The Brake control wire for the Brakes in normal operation will be fused by the Tow Vehicle. In 37 years I have never seen a Breakaway fused. I HAVE seen the Breakaway melted from the lanyard being pulled loose and the constant 12 volt draw by the brakes overheated the switch until it melts. Doug

Posted By: brulaz on 04/14/17 08:11pm

Thanks for the replies folks.
Have returned the line to its original un-fused state.


But now I wonder what folks do with a 24V system?

Run 12V to the break-away switch from 12V side of the 24-12V converter?

Or just run a wire from a 12V half of the 24V battery bank?

Think the latter might be the best ...

Posted By: DrewE on 04/14/17 10:06pm

brulaz wrote:

Thanks for the replies folks.
Have returned the line to its original un-fused state.


But now I wonder what folks do with a 24V system?

Run 12V to the break-away switch from 12V side of the 24-12V converter?

Or just run a wire from a 12V half of the 24V battery bank?

Think the latter might be the best ...


I would guess the latter, or perhaps have a separate (small) battery dedicated to the breakaway brake system. A great many non-RV trailers have a small battery for the breakaway brakes....




Posted By: Old-Biscuit on 04/14/17 11:12pm

Direct wiring to battery....no fuses

DOT requirement is FULL Battery Voltage for 15 minutes

Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

Posted By: dougrainer on 04/15/17 06:46am

brulaz wrote:

Thanks for the replies folks.
Have returned the line to its original un-fused state.


But now I wonder what folks do with a 24V system?

Run 12V to the break-away switch from 12V side of the 24-12V converter?

Or just run a wire from a 12V half of the 24V battery bank?

Think the latter might be the best ...

\
Explain this 24 volt statement. What RV trailers have a 24 volt system? Besides, WHAT RV tow vehicle would have a 24 volt system? Doug

Posted By: Espee on 04/15/17 01:16pm

I had my breakaway hot wire get pinched between the equalizer bars / frame on my last travel trailer.
Smoke everywhere in the reaerview mirror (scarey), and a mess to repair adjacent wiring. I felt like adding a fuse, but just rewired as per OEM... but being careful to route new wiring to prevent a relapse.
Jeff

2007 Ram 2500, 4X4, 6.7
06' Cougar 285EFS


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