No wiring diagram

[Rawze]

(10-18-2019 )DDlighttruck Wrote:  If I had to hazard a guess at this point, the marker lights and skirt lights are connected in the junction box to the same hot post. Then, also guessing, there’s a short to ground in the skirt light circuit. Thus causing the skirt light relay to turn on/off in tune to how fast the lights turn on/off, even with no skirt light fuse installed

When I was at my shop last, I pulled it outside and it started acting up. The fuse for the tractor marker lights blew. I unplugged the skirt lights, reset the circuit breaker and carried on into town

I've seen a bad bulb do that in the past too. Could be a bulb itself overloading the circuit, or internal filament shorts out when it is wiggled or heats up just right. on and off the whole circuit goes when they do this.

Just a thought, could be as simple as that, may not be your problem. Maybe look at any that are significantly brighter or dimmer than the rest?, or perhaps banging on each one while lit to see if there are any weak filaments?