Headlights not working

[Richard1969]

Looking for a bit of help my headlights are intermitent. I have traced the wiring back through and cannot see anything amiss. Looking at some of the other threads on here it says to check the main ground. Is that talking about the battery earth that goes to the engine block. I have just found a problem I had with the indicator only working one side was a wire into the block under the tank. Messing with the other block there which the headlight wires go into makes no difference. The headlight comes on when I press the pass switch.