need to connect wires to my motorized sofa bed in my e 150 van

Hello, The issue here is that conversion vans are made by third parties, and the schematics for the components installed come from the company who customized the van. If you have several wires running to the connection for the bed, you can check for power and ground at those wires one by one, or check for continuity form the wires connected to the back of the switch to those wires. Other than that, I would recommend having an RV tech look at it or look for a wiring schematic in the service panels.