Instrument bulb lighting...still dim

Good idea to go thorugh ALL the connections in your electrical system. Starting with the bulkhead. Get the right tools to remove the pins and sockets from the plastic bulkheads.

Mark all the positions and take reference pictures before taking anything apart.

Steel wool, sand, acid dip, brake clean, etc every connection. Make sure the female sockets grip the male terminal tight. Check for brittle wires.

Common brittle wire is the ones comming off the amp gauge. I've seen the wire inside fail, but they look fine outside.

The plug into the high beam switch gets fried commonly too. Check the inside condition of the plug for corrosion. And check the condition of the wires comming out of it.