basically the oem wiring will activate a relay which will switch a new wire you will run to the fan from the battery through said relay

 

Sorry to be clueless here but I'm in a little over my head at this point since I incorrectly planned to just use existing wiring. What is the simplest way to wire this so that its using the existing relay? Ideally I don't want to wire it directly to the battery, I'd like to use whats already available. Do I merely need to replace with appropriate gauge wire? I need details if you don't mind, many thanks in advance.

 

It would be so much easier to just use a new 70amp relay and run a 10 or 12 gauge wire to the battery. Just clip the connector off the old fan and attach new wires to it. 12v+ will go to the switching/control side of the new relay (assuming it's + switched). You won't need the ground from the oem connector (unless of course that's what is switched, in that case you'd need the ground and not the 12v+ from the oem connector.) Then have 12v+ from the battery to the switched/load side of the relay and then the other side of the switched/load side of the relay to the 12v+ on the fan. Ground the fan to the chassis or the - side of the battery.

If you wanted to use the factory harness you'd have to change wires into the pdc and possibly even further than that. The stock relay almost certainly couldn't handle the power that would be used from the new fan. Especially with the startup spike on the high side being nearly 60 amps iirc. It would be way more of a pain than it's worth to change the oem harness.

 

Can you link me to a suitable 70amp relay?

 

exact relay that came with my controller. you can find ones out there for cheaper, but this one is high quality and should be very reliable

http://www.ebay.com/itm/DAKOTA-DIGIT...f0e9c5&vxp=mtr

 

So that would just get wired in separate from the fuse panel right? Is there a way to tie the factory lead into it that is currently powering the existing relay? Just a matter of finding that wire?

 

yes, 2 pins on the relay are for the control (83 & 86 on this one iirc) and 2 are for the switched load (87 & 30 iirc). Again this is if I remember the pins correctly, pin 83 would get connected to the 12v+ (assuming it is switched) on the factory connector and 86 would go to the ground (either on the factory connector or chassis). Pin 87 would be connected to the positive wire on the fan and pin 30 would be 12v+ from the battery (through a separate fuse of course).

 

Thanks Matt. I'm going to digest this and make it happen. Wife has family coming into town so I won't be able to attempt until next weekend. You'll be hearing from me!

 

no problem

 

What amp fuse for the fused line to the +12 on the battery?