Help electrical problem under load

[Royal1500]

This problem has just started in the last week or so.. lights start to flicker and then dash lights up radio dies and wipers come on?? Any help is appreciated 

 

thanks

[L86 All Terrain]

Check your battery cables and make sure they are tight, many were coming loose from the factory causing some electrical glitches. There is also a ground cable mounted on the frame by the engine, make sure that is clean and tight. What year is the truck, original battery, how many miles? It could be a bad BCM too, they changed it out on my 2018 2500 when the fuel pump stuck on even when I pulled the fuses.