Topic: What is this thing?

[eigenvector]

http://www.powersedge.com/oemparts/a/hon/506c3113f870023420a31ddc/wire-harness-electric-parts

A part I have on my Sabre - called a Headlight sensor - it's part #14 on that sheet.
https://www.ebay.com/p/1983-Honda-Sabre-Vf750s-Headlight-Lamp-Sensor-OEM-04177/1711841695

I'm baffled by what that thing is - it's huge! 

[MikeSimon]

Do your instruments include a warning light for the function of tail-/stop-/headlight?

[eigenvector]

Yeah, there is an LED readout when the headlight burns out.

Jeeze, I can't believe they need something that big just to tell that the headlight/signals are out.

[MikeSimon]

Today they probably would not. In 1983 they probably did.