yes but then you need to pass wiring from the one side of the car under the dash to the other unless you decide to have two seperate switches left and right. and have an okward switch or two and cut the connectors from the mirrors wiring. Not very smooth installation and convenient.
otherwise if you buy two door wiring harnesses and proper switch you have a much convenier and professional installation like factory that does not deter to the van originality. Not worthwhile anyway to make your own wiring since dorr wiring harness is not expensive and you can easily find second hand used ones cheaply.