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I installed the Harley Speedometer Tachometer several years ago, and I love it. I'm trying to find out what the 2 lights (red and yellow) that come on when you turn the ignition switch on are for. Those lights go out after a few seconds, something about the o2 sensor setting or something like that. Anybody help? Specifically the ones under the tach.
Last edited by dustyinfla; Feb 22, 2026 at 03:01 PM.
The red circular light is the security system light. If you have a security system on the bike, that light will flash on and off every few seconds when security is armed and the ignition is off. It will also light and stay lit if you have active diagnostic trouble codes (DTC).
The yellow or amber light on the right is your check engine light.
It is normal for both of them to illuminate for a few seconds and then go out when the ignition is turned on.
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Harley Speedometer Tachometer
