BackOFF XP brake light installation question

[DrFaulken]

I put in a Blue Sea fuse box this morning and decided to go ahead and wire up my new BackOFF XP brake light modulator while the bike was "under the knife."

I wanted to run "Mode 2," which is a few flashes and then a steady on. The wiring diagram made it look pretty simple:

I cut the yellow wire coming out of the wire loom on the right side of the bike (sitting on the bike). I put a male spade connector on one end of the yellow wire and a female spade connector on the other end.

I put a female spade connector on the solid red wire on the BackOFF unit. I put a male spade connector on the red with white stripe wire.

I ran the ground wire to the grounding bolt on the Blue Sea fuse box.

So I basically have this:

12V -> yellow wire -> solid red wire -> BackOFF XP unit -> red and white wire -> yellow wire ->tail light

and then the ground wire.

However, when I turned the bike on the brake light wouldn't work. The tail light illuminated, but no brake light at all, let alone any flashy flashy.

I disconnected the BackOFF unit and plugged the yellow wire back together, and now the brake light works again.

What have I done wrong?

 

[buf2phx]

My only guess is that you wired it in backwards. Unplug your spade conectors and check which one has power with a test light when you actuate the brake lever or pedal. Aside from that, bad BackOff unit.

 

[kolonial72]

There have been issues with LED brake lights. Also I knew one guy that had his all wired up, and it would not work. He disconnected/reconnected a couple of times, and it started working. Some kind of minimum effort interlock?

EDIT: Did you tie in to one yellow wire? You may need to tie into two yellow wires (one for each brake light) with your red/white stripe wire. Or did you tie into the wire before it splits to each light?

EDIT 2: Also, are you certain the ground on the fuse box is good?

 

[DrFaulken]

Good questions.

I got the XP unit, which is supposed to work with both LED and incandescent bulbs.

I tied into the yellow wire on the right hand side at about where the front of the seat adjuster tray is under the seat. I am not sure if that's just a single brake wire or if it split yet. Does anyone else know?

Yes, the ground on the fuse box is good -- I wired up a pair of auxiliary lights to it and it works fine. Good question though

Any other ideas?

There have been issues with LED brake lights. Also I knew one guy that had his all wired up, and it would not work. He disconnected/reconnected a couple of times, and it started working. Some kind of minimum effort interlock?
EDIT: Did you tie in to one yellow wire? You may need to tie into two yellow wires (one for each brake light) with your red/white stripe wire. Or did you tie into the wire before it splits to each light?

EDIT 2: Also, are you certain the ground on the fuse box is good?

 

[kolonial72]

I just looked at my (Gen I) wiring diagram and took a peak under my (Gen I) seat. Though I did not visually verify this by looking into the loom, it looks like the yellow wire of which you speak splits in the tail assembly. Your yellow wire should be the one you want, barring radical wiring differences between your bike and mine.

What I'm saying is, I dunno. Consider the old try, try again routine. Disconnect everything, wire it all back up, see what happens. If it still doesn't work, holler at Signal Dynamics.

Often I will recommend mechanical agitation, but I'm told the little electronic bits inside the module don't like being shaken/slapped/hammered.

 

[johnny80s]

Good questions.
I got the XP unit, which is supposed to work with both LED and incandescent bulbs.

I tied into the yellow wire on the right hand side at about where the front of the seat adjuster tray is under the seat. I am not sure if that's just a single brake wire or if it split yet. Does anyone else know?

Yes, the ground on the fuse box is good -- I wired up a pair of auxiliary lights to it and it works fine. Good question though

Any other ideas?

There have been issues with LED brake lights. Also I knew one guy that had his all wired up, and it would not work. He disconnected/reconnected a couple of times, and it started working. Some kind of minimum effort interlock?
EDIT: Did you tie in to one yellow wire? You may need to tie into two yellow wires (one for each brake light) with your red/white stripe wire. Or did you tie into the wire before it splits to each light?

EDIT 2: Also, are you certain the ground on the fuse box is good?

Swap the wires. LEDs only light if the voltage is going through them correctly. Reverse the voltage and they don't light. Also you could wire it up to your battery to test it out. That will let you know if it works at all.

 

[DrFaulken]

Well, it was definitely operator error on this one. I had the wires wrong.

I wired my fuse block and auxiliary lights yesterday. I guess I had been looking at wiring for so long I was thinking "solid red" and connected "red with a white stripe." Doh!

Thanks for the sanity check, I went out, put new connectors on, and it worked great.