I’m redoing the wiring on my 2002 Sportster, I cut the wiring harness up the neck of the bike, exposing all wires to read with a multimeter.

I expected one of the Orange/white wires to be 0V, then 12V when I press the brake pedal. None of the wires I checked have any effect when I press the brake pedal.

I already hooked up my brake’s running light, and the brake light to my red/yellow wire. However, I need to figure out how to get power to the red/yellow wire when I press the brake pedal.

Am I wrong, or should one of these orange/yellow wires be hot when I press my pedal?

Can anyone help or recognize any errors in my process here? I wana ride!

Note: this cut all the connections to front controls including front brake switch, if this matters/causes issue.

 

On my 1991 I have an orange and red wires at the rear switch. According to my wiring diagram, it looks like the orange should have 12V, which gets sent to brake light via the red wire. Have you looked at a wiring diagram for your year bike? I don't have an orange/white wire, just orange and red. You can find a wiring diagram on the H-D service portal website. Good luck!

John

 

I have a wiring diagram, but I am not seeing what I expect on my bike.

Let’s ignore colors just because we have different years. The wire you’re using, it goes from 0v to hot when you press the brake pedal? I can’t find any wire that does anything differently when i press my brake.

I cut my harness, so maybe I need to bridge a connection.

 

According to the wiring diagram for the 2002 Sportster, you should have power on the O/W wire from the 15 amp accessory fuse. The O/W goes to one side of the rear brake light switch and the R/Y should bring power the brake light when the switch closes.

 

I severed the wires from the frame tube. I have all these wires exposed. So my red yellow wire is open. I’m wondering what I connect it to. I’m assuming the OW that goes to that switch (but wouldnt that mean a OW wire would switch from cold/hot when I press pedal)? I can take a pic if it helps. I might just be misunderstanding what i’m doing, i’m winging it.

 

Why don't you start at the Accessory fuse to see if you have power there. The fuse is fed by a R/GY from the ignition switch. The O/W then goes to the rear brake light switch. When the shitch is closed then the power goes out on the R/Y wire to the brake light.


2002 Wiring Diagrams | H-D Service Information Portal

 

I believe my orange wire is hot (12V) all the time, the brake switch just connects power through switch to the red wire to the brake light and ground. But, even though 1991-2003 are very similar, wire colors may be different.

John

 

First I gotta ask...

Why did you cut the wiring off?

The Orange/White wire is the accessory circuit, it will be powered when the ignition switch is on.

Ok, here is the electrical path for the brake lamp:

The power for the brake lamp is from the accessory circuit (Orange/White wire), through the brake switch (front or rear), to the brake lamp via the Red/Yellow wire.

Here is the path when the brake pedal switch is activated:

 

Very nicely done Dan. I still don' know how to take a screenshot and post it. And you even did it with colors. Very nice.

 

It was a big stretch of my computer skills, took me about 10 minutes (at least).

My grandson or granddaughter probably could have done it in about 1 minute...