Brake line fuse location

[mobilcastle]

Does anyone know where the fuse is located in the main brake wire? Thank you for your info.

 

[danemayer]

Hi Steve,

I've attached the wiring diagram for the seven-way plug that shows the brake wiring, among other things. I don't see a specific mention of a fuse for the brakes. The 50Amp fuse shown near the battery looks like it would actually be the manual reset circuit breaker on the buss bar near the battery. The breaker as shown in the diagram is between the battery and power converter and I suspect the diagram is not accurate. I say that because if the manual reset breaker tripped, until you reset it, there would be no power to the brakes. It's more likely there's a separate wire from the battery to an auto-reset circuit breaker that supplies power to the brakes.

 

[mobilcastle]

Dan, Thank you for the diagram-I will follow the wire and see where it goes. I will post when I do this rewire. Steve

 

[brianharrison]

There might be a specific trailer brake fuse in your truck?

 

[TedS]

I don't believe there is a brake fuse on the trailer. There would be a fuse in the tow vehicle in the brake controller circuit.

 

[evolvingpowercat]

There is no fuse in the 12 volt line running from the 7 way connector brake pin to the brake actuator coils. I believe this is industry standard and may actually be a RVIA requirement.
There is also no fuse in the 12 volt line running from the 12 volt terminal block to the breakaway switch. There is the prior mentioned breaker in the terminal block that the 12 volt battery connects to. In my Edge that terminal block is labled as having a 60 amp circuit breaker inside.

 

[danemayer]

When the trailer is unhitched, the trailer battery has to power the brake circuit if the break-away switch activates. I think that would put 12V on the wire to the break-away switch all the time. There would need to be a fuse or circuit breaker to cut power in case of a short on the wire going to the switch. I'd also expect that circuit to be independent of the battery cutoff switch.

All this would be independent of whatever protects the tow vehicle wiring.

 

[evolvingpowercat]

I agree that it would be better if there
was a fuse or circuit breaker in the wire from
12 volt to the breakaway switch but
there generally is not.

I suspect the breakaway switch would be
a weak link and might protect the wiring
if there was a short on the brake wire
and the breakaway switch operated.

Another poster advised carrying a spare
breakaway switch "just in case" it is
a $15 cost item.

Here is the 12 Volt system
that does not go thru
the 12 volt distribution
fuse box...

Trailer 12V Battery
|
|
60A Circuit Breaker
| (in terminal block)
|
+----- 55 Amp max output
| 110V to 12V converter
|
+----- 12 Volt battery side
| of breakaway switch
|
+----- 12 Volt pin on 7-way
vehicle connector

Theoretically, all these wires should be large
gauge such that the 60A breaker will trip
before the wires fail, but on my Edge the
wire to the breakaway switch and vehicle
connector could melt thru before the 60A
breaker protected them.

Trailer Brake circuit:

7 Way Connector Brake Pin
|
|
+--- Brake side of breakaway
| switch
|
|
+---------+ Splices in wiring harness
| |
| |
Axle 1 Axle 2 Brakes, etc.

 

[TedS]

I don't want a fuse in the line to the breakaway switch. I want power always available in the event of a breakaway to activate the trailer brakes.

 

[dave10a]

Does anyone know where the fuse is located in the main brake wire? Thank you for your info.

What is the reason for your question?

 

[mobilcastle]

I am going to run heavier wire to my brakes

 

[dave10a]

I am going to run heavier wire to my brakes

Why-- are you having a problem of some kind?

 

[JohnDar]

Why-- are you having a problem of some kind?

Curious. Would a heavier gage of wire give some added protection to the exposed wires of the brake system in the event of a tire shredding? Seems loss of brakes goes hand in hand with a tire failure in a lot of cases.

 

[mobilcastle]

I have been on vacation. I am going to check my volts and amps at the brakes to see what the readings are. There are are a number reasons to rewire. Home run wiring would make sure if you lose one brake you will only lose one and not others being in series. Grounding each brake would be better because if you lose the factory ground wire that is common you will have no brakes at all. Heavier wire will carry more volts and amps if needed. I am going to go from 12 guage to 10 guage and use seperate grounds. I hope this answers the questions I have recieved.

 

[TedS]

The brakes now are not wired in series. They are in parallel. Heavier gage wire will reduce voltage drop and allow more current to flow to the brakes. Independent grounds sounds like a good idea.

 

[mobilcastle]

The brakes now are not wired in series. They are in parallel. Heavier gauge wire will reduce voltage drop and allow more current to flow to the brakes. Independent grounds sounds like a good idea.

Yes your are correct.