My Garmin AUTOMOBILE CIGARETTE LIGHTER PLUGS contain considerable solid-state circuitry for regulating and conditioning the automobile-provided power supply (nominally, "12 VDC").
Thus, before you go cutting the cord and replacing the plug with a connector to your bike's power supply, EXAMINE THAT PLUG. If you find it contains a circuit board, transistors, diodes, toriods, etc., etc., lots of electronic components, jettisoning the cord and connecting the GPS receiver directly to the vehicle's power supply may result in unwelcome consequences (e.g., frying the GPS receiver).
If you simply cut off the plug and throw it away, here's what you might be discarding (actual image of genuine, authentic, Garmin power plug, case open):
And, another thing . . . while the Garmin GPS receivers may be rugged as all get-out, the power plugs may not survive the G-loads of a KLR's relentless vibration. Notice the copper-colored, doughnut-shaped component in the upper case half shown above. That, friends, is called a TOROID
, or "choke," or maybe other electronic nomenclature.
Anyhow, my KLR shook so much it separated this component from the original electronic suite of the power plug.
Now, ALL Garmin GPS systems may not employ the power conditioning and regulating circuitry shown; however . . . the Etrex system I bought does.
YMMV ("Your mileage may vary.")