Any ideas about this button and switch?

Hi everyone, I was wondering if anybody had any ideas about what this button and switch might do? I got the truck used and found them inside the coin tray. I have no idea what they're wired to, and when I push/flip them, nothing seems to happen. I thought the switch might be an ABS kill, but nothing seems to light up or do anything. I also have what seems to be a phone or sub remote cable that is tucked between the dash and front windshield if anybody has an idea what/where that might go to. The truck came with an aftermarket HU, remote start, and a rear DVD player. Any ideas are appreciated!

 

I know that some aftermarket DVD systems require you to have the truck in park and to cycle the parking brake off and on before the video screen will work. I bet those switches are there to imitate the intended connections to the truck's electrical system so you can watch tv going down the road. Probably mounted there so they are not easily seen when pulled over.

 

Button is likely to disable/enable an alarm system that arms passively (valet mode).

 

Either answer would make sense to me. I've never tried playing a DVD on the HU or player, so that would make sense as to why I didn't notice anything. Thanks for the help guys!

 

Might have been for a train horn since the button looks to be momentary. The switch would just either control the solenoid of the horn itself or the compressor.

 

If it is, the dealer/PO removed it and left the switch in. Oh well, I have no use for a train horn lol