Possible bad headlight light switch?

[htbetz]

When ignition is on the interior lights blink every so often and the dimmer dosen't work.
When the ignition is off the dimmer works but the headlights don't come on. I switched relays with no luck.
Not having the dimmer working dosen't bother me but having the interior lights blinking does.
I suspect it's the switch but before I order one....
Any ideas?