Yep, happens a lot.
You can test for voltage on High-Beam either at the light connectors, OR at the dimmer switch. Or both to make sure the wires are doing their jobs.
The switch is the most common culprit, but it's not unheard of for both high-beam filaments to be burned out either. You may just need new lamps/bulbs.
But testing will tell the tale.
If you check your grounds and they seem good, try connecting a temporary jumper wire as ground, directly from the battery to the core support sheet metal to see if that helps.
Remember that anything grounding to the core support metal is relying on it's ground path through the old welded junctions at each corner (inner fender skirt, or apron) and after so many years of rust, paint, or other deterioration, the ground connection may be almost gone.
And that assumes of course, that you actually still have a body ground? Is there a component of your negative battery cable that goes to the body directly? Or does it only go to the engine block?
If only the block, then you need to add a wire (10ga works) from the battery negative to the body.
Paul
