I'm having a problem with my 1983 Nighthawk 750.

I noticed that the low beam was burning dim.
After replacing the bulb the problem was still there.
I discovered that the high beam and low beam filaments are both burning when it's on low.
I've inspected the high/low switch and the wiring harness and they both look good.
I thought that maybe I have a bad headlight relay, but if this bike has one I can't find it.
Thanks in advance for any ideas....................