is there a way to wire up the ac elctric fan so that it has automatic control and manual with a flip of a switch?

You could use a relay (one of the Hella-types) that "switches" between a "normaly on" (relay energised) & a "normaly off" (relay off)--use the terminal "30" to the fan & terminals "87" & "87a" to a fused + supply & the normal A/C power supply & of course switched (forgot the term #s) & ground--I'd wire it so when you turn your switch on in the dash, the relay would supply fused + supply--use a good relay that is rated at least 20A & fuse the power supply lead for 5A less(=15A) that way you blow the fuse first!! I believe that the real Hella units are rated at 30A.

 

Hope that helps--I can scratch out a wiring diagram if you want--

 

Dean

 

Almost forgot--either wire your switch to Ign + or use a lighted switch--don't want a dead battery!!