My best guess it that the unit on the roof is the receiver of some kind as for the box it may be a additional equipment for that aids with the remote control operations of the locomotive.
@pmonlux - You know, I'm pretty sure Dave has you blocked, so he can't even see your ridiculous long-ass post? Just stop doing this already. You come in, and literally hijack his posts with giant images that take 5 minutes to load/scroll through, and disrupt the threads main purpose.
My guess, the loco is a DPU. Since the cab says “REMOTE CONTROL EQUIPMENT” The box on the nose could be the radio equipment. The paint looks relatively fresh, so that could also suggest being rebuilt. Back in the 70’s, radio controlled locos built by EMD had extended noses to house the hardware. Since there isn’t any room to do that here, that could explain the location of the box.
My guess, the loco is a DPU. Since the cab says “REMOTE CONTROL EQUIPMENT” The box on the nose could be the radio equipment. The paint looks relatively fresh, so that could also suggest being rebuilt. Back in the 70’s, radio controlled locos built by EMD had extended noses to house the hardware. Since there isn’t any room to do that here, that could explain the location of the box.
The box on the top looks like the radio control system based on the appearance of short stubby antennas. I agree with Javier that the outside unit on the side of the nose is an A/C unit.
REMOTE CONTROL EQUIPMENT most likely means that the locomotive is used in switching with a conductor or engineer on the ground moving the locomotive around like on a model railroad using an oversized DCC controller. I saw this operation once. When the conductor needed to move to another location, he climbed aboard the engine and stood on the gangway, although the cab door was open. With the weather being very hot now, it's possible that the conductor or other crew members will go inside while moving the locomotive to another part of the yard rather than stand on the gangway in the sun.