I recently purchased a high performance fluidyne electric puller fan and I have a few options.
Option 1- Hard wiring the fan to the battery with a mechanical switch inside the cab.
Option 2- Hooking up a relay to a temp sensor which will turn on automatically when temp rises, same idea as the thermostat (idea so for need help finding signal for relay)

So what do you guys think? People who are going for option 2 I would ask you for some sugestions on finding that signal for the relay.

Help Me Damn It~!

The best way would be of coarse the relay/temp sensor, it's also alittle more complicated. Summit has a kit or you could buy all the parts seperately if you have the skill.
http://store.summitracing.com/partdetail.asp?part=PRM%2D18907&view=257#largerimage