I use these relays for a wide variety of uses. Here's some examples:
* Lighting the BMU indicator to tell me that my bypassed sidestand switch is down
* Making my LEDified side reflectors flash off when the turn signals flash on so that they serve as both running lights and turn signals
* Making the LEDs in my tail light "wag" with the brake light flasher
I use small PCB (printed circuit board) relays that I purchase on Fleabay for $1-2 each if you buy several of them. Search for "12V DPDT relay." They're smaller and less expensive than using the standard Bosch type automotive relay.
You can find them capable of different loads but the ones I use a lot are the orange ones that are rated to handle 2 amps at 30V. Since K bike voltage regulators generally limit the voltage to 14 or so volts that means that they can handle approximately 4+ amps or 50 Watts. More than enough for LEDs and a lot of other electrical devices.
Sometimes these relays are polarized, sometimes not. It's easy to test them using a 9V transistor battery.
Once I've figured out the polarity of the positive and negative trigger terminals and the input and output terminals, I clip off the terminal pins that I won't be using.
Then I solder (easiest if you use some flux) wires to the terminal pins:
In order to waterproof them and keep the terminal pins from bending and breaking off, I then wrap them in electrical tape, hang them upside down and fill the tape with JB Weld or some epoxy:
When the tape is removed Voila! - a waterproof mini relay:
edited by scott_ 10-12-13 to replace missing photo's
