What is this electrical part?

[Nelson]

I took my XS650D with Velorex sidecar apart to restore it in 2010 or there abouts. Life got in the way... now I am back to working on it. I got the motorcycle and sidecar frames and parts back from the powder coater a few months ago. Also parts from the chromer. Ive been putting it together slowly but surely.
Right now I am working on the wiring. I have a new wiring harness from Mikes XS and would like a chart showing how to route the harness on the frame if anyone has one.
I also have a part that is still plugged into the old harness but which I can't find on my electrical diagrams.

It is black, about 2" wide x 1" thick x 1-1/2" high with a mounting tab for two screws on top. Three wires go to it. A black wire, a red wire and what appears to be a pink wire. The black wire connects to a terminal on the device that has a yellow wire emerging from the device itself and going to the black wire terminal.

Thanks for any help you can provide

 

[5twins]

That's an aftermarket item, maybe a relay? Were dual horns mounted? I think pink is usually a horn wire.

If you look in the back of a factory shop manual, there are usually wire and cable routing drawings.

 

[Nelson]

Thanks. It had aftermarket horns so you are probably correct. I've been working from my Haynes and Climer manuals. As I recall I do have an OEM Yamaha shop manual somewhere. I'll just have to spend some time searching.

 

[gggGary]

From a later special but the general idea.

 

[Nelson]

Thanks Gary. My OEM service manual did not have a cable routing guide. I really app;riciate this!