1991 Mazda b2600 Repair Question
No relay that I am aware of. Sounds like a problem with (multifunction switch/combination switch). If you want to test further, Use a voltage tester at headlamp connector. Red wire with white tracer is voltage for high-beam. Red wire with black tracer is voltage for low beam. Black wire is ground.
Okay thanks I will try that too. But I did change the switch and it is the same result.
2 questions asked
At the light switc. The red wire is hot, correct. Use a jumper between red wire and red wire with white tracer. Use the jumper also with red wire with black tracer. The lamps should work. If not, something wrong with the bulb, lamp connector or wiring circuit.
this switch has points in it and that is what gets fouled up i fixed four of them last week get a can of switch cleaner and a tube of switch grease, take it apart and clean with a points file and 600-1000 grit sand paper. don't loose the steelies and springs under the white cover you half to pull first to get to one of the clips. notice the position of every thing and put it back that way.
this is the switch and what it looks like
clean in between all points, switch will look like new after cleaning and work for years. make sure that the head light on and off switch on the dash is in the same position as the switch block. to do this plug all the plugs on the switch in (witch needs to be done first when reinstalling) turn on key and turn the lights off on the nob and switch( if the nob is frozen its installed wrong)