I am going to be mounting two small fans in front of my A.C. Condensor to act as pushers, and I want them to run all the time. I was going to ground one wire and then run the other to an accessory power source, so do I still need a relay? And if so what do you suggest? Thanks

 

You might be ok, It all depends on how much current that the fans use.

By using a relay, you could tap power right from the battery, and run it to the relay/ fan combo and then use that aux fused circuit to just activate the relay when the car turns on, this way you are getting less resistance do to wiring and you wont have a problem with power as long as you use some decient wire from the battery and an in line fuse.

 

What is the current rating of the fans? You say small but if the average run current is more than a few amps use a relay. Any 12 volt relay capable of handling about double the average current should be fine. Wire the coil to work off the ign to energize it and the feed one end the contacts through a fuse to the battery other to the fans. Auto parts places, RV places as well usually have 12 volt heavy duty relays with mating sockets for around $15-20.