Tripmaster switch to control lights

[duncan]

The tripmaster has three buttons. Two of the buttons are only relevant when in the "trip mileage two" mode.

I was thinking of tying into those buttons to control some relays that turn an extra light on and off (more light to improve my nightime depth perception).

I was going to put a "master" switch in the dash, but then have easy thumb access to dim down for oncoming traffic.

The trip computer/speedometer holds these lines normally at 5 volts (checked with my multimeter). The momentary switch is a direct connection to ground. I was going to use an op-amp to detect the momentary pulse to ground and turn the relay on and off.

Anybody see any gotchas in here? Any good ideas to add in this circuit?