Headlite problem?

[DCracer25]

Ok got the trike out for a long run (81 1100 ) and was on my way back after dark on the highway when I switched from low beam to high beam and the headlite dimmed then slowly came back up to power and it did this everytime I switched back and forth. need some help here, not sure where to look first. Battery is new and seems to stay charged up. I did clean all grounding locations.
I need to find the problem before I or my wife rides this at nite again.

[rover]

headlight

You may have a filament (high beam or low beam) burned out. There is a switch (?) that will switch the light to the working beam at reduced brightness. Unplug your headlight and check with an ohm meter for a burned circuit.