Brakes blowing fuse

[snakemeister]

 When I apply the brakes on my 1997 Tourer it blows the fuse that controls my horn, turn signals and rear tail light. Is there any usual suspects for this?

[Skinhead]

You probably have a short in your harness to the brake light, or on of the switches.  I had a similar problem and it took me a while to find it.  It was some wiring I added in the tail light that was shorting to ground.  If doesn't take much, just a break in the insulation, or a wire pinched.

Also check the wiring under the rear fender, sometimes the wires aren't located properly and rub.  Those are my best guesses.

[Michvalk]

First place to look is the connector under the rear fender. It's easy to reach from the back

[pancho]

First place to look is the connector under the rear fender. It's easy to reach from the back

Plus, if you unplug it, it isolates a lot of hardware to help isolate the problem.

[sandy]

If you have a conventional tail light bulb, check it first. If one element is broken, it can short over to the other element and do what you're seeing.

[rhinor61]

Blowing fuses can happen several ways...

A. +12vdc wire going to ground
B. Over current draw on the circuit, the amp rating is to protect the wires and the down stream devices from catching fire.

There is no way element to element on 12vdc will ever blow a fuse, its the same 12vdc.
each element is just a different resistance.

replace fuse and test each item on the circuit 1 at a time. Get you wiring schematic out and follow the wires/devices.

...

[mike72903]

Blowing fuses can happen several ways...

A. +12vdc wire going to ground
B. Over current draw on the circuit, the amp rating is to protect the wires and the down stream devices from catching fire.

There is no way element to element on 12vdc will ever blow a fuse, its the same 12vdc.
each element is just a different resistance.

replace fuse and test each item on the circuit 1 at a time. Get you wiring schematic out and follow the wires/devices.

...

But if the elements are shorted together they would be in parallel.  Resistance's in parallel reduce total circuit resistance thus more current flow at the same voltage.  Ohm's Law I=E/R

[indybobm]

There is no way element to element on 12vdc will ever blow a fuse, its the same 12vdc.

Never say never. It might be unlikely but not impossible. One side of the winding would be resistive, the other side is straight +12vdc to ground if the winding is shorted to the bulb case. Seen it before.

[rhinor61]

okay... maybe it could happen else where,
but on a TOURER the tail light and brake light is on the SAME 15amp fuse, both loads are happening ALL the time.

and I dont blow a fuse when I apply my brakes.

[cokebottle10]

An old trick is to solder a single element 12 volt light bulb across a blown fuse (1156?). The voltage will pass through the element to the wires. Remove the loads (Lights) downstream. Now you and can move the wiring harness around and if it shorts it will light the light. The light acts as a fuse.

Thanks, David in Fletcher NC.

[Valkpilot]

okay... maybe it could happen else where,
but on a TOURER the tail light and brake light is on the SAME 15amp fuse, both loads are happening ALL the time.

and I dont blow a fuse when I apply my brakes.

On the Standard and Tourer, brakes, turn signals and horn are on the same 10A fuse.  Tail light and meters are on a different 10A fuse.

On the Interstate the brakes and tail light are on the same 15A fuse.

http://www.rattlebars.com/valkfaq/schematics/rpage03.html

http://www.rattlebars.com/valkfaq/schematics/rpage03i.html

http://www.rattlebars.com/valkfaq/schematics/index.html