Dodge dakota 2003, 6clyinder,2wd 4dr

anytime it is wet outside,rain, snow, damp the pickup will not fire.i have stayed over nite at a friend’s and not able to leave for a day or two waiting for sun or dry air? Where do i look for problem? is there a spray for eng area?

Replace plug wires, distributor cap and rotor if it has them.
Could also be the coil if it has only one.