[Jimbo]

I just orderd the Engineer's aux rad with the high CFM fan. MY question is after looking at the wiring dia. that came with the fan is: The Dia shows a fan relay with the system wired up directly to the 12volt post in the little red box by the fuse box on the driver's side fender bypassing the ign. switch. Why do I need the relay when it appears to me that all I have to do is run a hot line with a fuse from the post in the red box to an OFF/On switch and them back to the fan. One of the wires on the fan would go to ground. What do you think?

 

[jlawles2]

The relay will take a low amp signal from an electric thermostat and activate the high amp fan. This will also let you run the thermostat from the key (low amp draw) to activate the relay to control the fan and be key dependent for power.

 

[Jimbo]

This system doesn't have a thermostat like some systems, it is just an on/off switrch acording to the wiring dia. that I got.

 

[JC1843]

The on/off switch cannot handle the high amp draw of the electrical fan for extended length of time. It will burn up-- along with wires, and that can cause a fire!

Be sure you use at least 12 gauge wires from the battery to the relay. The switch wires can be 14/16 gauge, because they only turn on the relay.