Hello friends.
I was installing a trailer hitch this morning and there were three boxes on the way, bolted to the frame.
There were two boxes bolted to the each side of the frame at the last hole by the bumper so one box on the right side and one on the left side.
Those boxes are connected to a third box with 4 thin wires. That third box is connected to another box thats in turn bolded to the frame on the driver side.

Initially I though it was something to do with the trailer brakes so I disconnected the boxes. When I tried to crank the van it didn't. The dash didn't even light up. So wen I reconnected the boxes van fired up and ran just fine.
Below are the pictures of the boxes in question. If anybody know what those boxes are please help me identify them.

Thank you.

 

I don't know at this time what they are for, but it's a good thing you found them. From the wiring it appears to be some aftermarket addition . Also if any of that wiring loses contact and your vehicle refuses to start you now have someplace additional to check.


It appears to be an aftermarket back up warning/ alarm system. Don't know how it is wired in to prevent the vehicle from starting, but if it is what I think it is , it should only get power when the vehicle is placed in reverse. Looks like it is manufactured by Ross since it shows their own part #.