Headlamps on 1992 Infiniti M30

I have a low beam headlamp only on the passenger side and a high beam headlamp only on the drivers side. I have checked everything I can think of. Good ground. red wire to the headlight bulb shows small amount of current on tester, but lights will not burn. I replaced bulbs.

Asked by for the 1992 Infiniti M30
Sounds like. A bad. Relay or main switch