I’m about to sell, with some sadness, my 1978 Honda CB400A “Hondamatic” motorcycle.

I have one last problem with it – that’s been baffling me for over a year.

When I consolidated the speedometer and “idiot lights” to a svelte new cafe racer style chrome LED-based single instrument, I found that its neutral light was always on, no matter what gear.

So I finally figured out a clever (if I may say so) way through research to use the “proverbial $7 part” from in-stock Radioshack – a RELAY switch!

Here, I describe and show the problem, step through a bit of the bike’s electrical system, and show you how I used a relay to fix the problem.

I’ll be sad to see you go, little Decaf!

The awesome video learning tutorials I used on Youtube to determine relays were for me!:

RELAYS – How to wire and how they work TUTORIAL !!

How An Automotive Relay Works and How to Wire ‘Em up

(thanks, guys!)