Right side running lights blowing fuse

[Russell Hackler jr]

My 2020 GMC Sierra 3500hd AT4 started blowing fuse 42 that powers the right side running lamps, and the fender flare lights. The turn signal and brake lights all function correctly. The only thing I did before I noticed they were out was load up my snowmobile for the first time (first substantial weight on bed). 
This led me to this site where I saw another guy found a wire pinched between the bed and the frame mount. That would match my situation- loaded up the bed and finally pinched the wire, but I can’t find any pinched wire. 
It’s at the dealer now and they are saying my Boost Auto Parts smoked fender flare lights that I installed voids any warranty and is likely causing the short. We all know this is BS because the alarm blink and turn signal lights in the boost lights still work. 
Sorry for the long post, has anyone found a solution to fuse 42 park lamps RT blowing? Truck is stock other than the aftermarket fender lights and a sled deck. 
Thanks Guys!!

[Another JR]

Unplug all your non-oem lights and see if it still blows fuses. If it does, it’s the factory wiring that’s the problem. 

Edited January 23, 2022 by Another JR

[Russell Hackler jr]

1 hour ago, Another JR said:

Unplug all your non-oem lights and see if it still blows fuses. If it does, it’s the factory wiring that’s the problem. 

Boost auto parts recommended the same thing. I’ll see on Monday if the dealership will let me access my truck to do that. Thank you for the reply, Another JR!

[Russell Hackler jr]

Found the problem. When my truck was last in the dealership for warranty work, they pinched the wires for the fender flare lights in the fender liner then put a screw through the wires. Of course they won’t accept any responsibility for their mess up. I’m out $360 but at least my lights work now.