Does the truck run just one shift or is there a second and or third shift also......might want to check into what the other shift operators might be doing with/to the truck to cause the fuse to blow????

Thank you. I will check into that. Do you have a guess for each scenario? Thanks.

Have you actually checked the fuse PRIOR to trying to start the engine in the morning? Or do you try to start it only to find that the fuse is blown.
It might help to know whether the fuse is blowing during the night with the key switch off..............or if it blows as soon as you turn the key for the first start of the day.