that's a typical failure mode for those switches, the left and right or the up and down stop working. I tried to fix one but there is circuit board inside that burns out or shorts.

I have a good working one but the white "arrows" have been erased from use, also the grey plastic wiring plug needs to be matched to the harness plug in your van, they used a small plug and a large plug, I have both. can you take a picture of your switch and wires with the plug? (you will have to remove the door panel to remove the switch assembly, it is held by two 8mm nuts).

if you want it, pm me.