Headlight upgrade harness, upgraded bulbs or brightboxes?

Thanks for the quick reply. There's a short somewhere in the wiring that a little jiggling fixes temporarily.

 

A harness will be controlled by the left side connector, as you want the leads as close to the battery as possible which is on the left. So if it is shorting out to not working, it may not help. If you jiggling it fixes the issue, seems like it would be the connections in the plug, as it seems unlikely the wiring itself would be damaged or break.