Electrical Gremlin

i have a Kenworth T800 back in my shop with the same light issue its come in for 4 previous times but always seems to fix its self after hours of tracing wires the issue started with being the dash panel, tail, and both fender marker lights staying on all the time till the battery was disconected now i only have dash panel light and the pass. fender marker light on when all switches are off and key is off any ideas. if i ground a power wire on my panel dimmer switch the panel lights will shut off

 

we have unhooked wiring harnesses on the firewall and found power backfeeding through the wiring harnesses not sure where its coming from

 

we have found the dome light fuse powers the panel lights with no control over the panel dimmer with the dome light fuse in once that fuse blows or is removed the panel dimmer works as it should but does nothing with the exterior lights that stay on! we have removed fuse panel to check for crossed power there and there is no crossed wires. where else would these 2 be connecting?

 

Thank you Gentlemen it was something as simple as a few broken wires burnt out bulb and a wire hooked up to the wrong switch thanks to the shop down the road on the wire being hooked up wrong