'88 ford e350 blower fuse location?

i have no juice at the switch....fan works if i run juice direct to it....all fuses in box chk good.....4 wires at switch none are hot with ign. on tried panel selector in every position......oh oh all 4 wires have continuity to ground??......hot wire is grounded out somewhere....run a new hotwire or??....anybody got any insights?.....cybernomadus@yahoo.com (insights?.....cybernomadus@yahoo.com)