I got a little cheap meter. The needle moves when I touch these polls at the same time. The fan has 3 wires also.
A relay typically has five terminals: two go to the relay coil - that operates the switch arm one is common that is electrically connected to the arm of the relay one is normally open it is a contact that becomes connected when the coil is activated one is normally closed it is electrically connected when the coil is not activated
I looked in a Haynes book and also saw a 20 amp fuse in front of the relay, do I need to put a fuse inline too? Can anyone tell what is what by my drawing? I have an extra battery, is it possible to wire the fan out of the car first using "+" and "-" on the battery terminals?
on the 3 posts on the fan, one out side one is the ground, the middle is the power for slow speed, and the other out side one is high speed. usullay ford had a - and + sign cast in the plastic over the out side termals. it usually really small and hard to see but there. i do belive that the bottom terminal is the ground when the fan is standing up in the factory installed postion but dont hold me to that. you can put wires on the two outside posts and then touch them to a bat. see wich way the fan blows and if its blowing the wrong way, switch them.
Okay, I have the "-" wire and the "+" on the fan. I will hook them to the outside post. What do the 12 volt source wire go?
STOP!!! the "-" wire ...on the fan goes to a ground to the frame. the "-" pole on the relay goes there also... the 12 v source pole/wire goes to the battery...there should be a switched on pole also... ...Frank...
Just some new info. If anyone is looking for a 75 amp relay, try a local place that sell semi truck parts. I just picked one up from Crows for $33. After the whole weekend of searching & calling around. The big electronic stores did not have one either that use 12v.
