ajfran3

Hello I bought a Derale dual fan transmission cooler. I found a place to mount it up front and test fitted it looks real good but I need to get it wired now for the fans. I bought a Derale relay that is rated to run them both. Can someone explain to me where I'm hooking up the wires. I plan on just having a switch to turn on and off the fan when needed I have a temp gauge to monitor the temperature. Thank you for any help

Saudade

For running a switch to operate the fan I would connect the Switched Power 12v wire to something that's only powered with the key in RUN, then run the ground through a switch on the dash. You should have plenty of options in the PDC. This allows you to turn on the fan when you feel the need to do so, but not allow the fan to run with the key off. Also running ground wires to switches ( not the hot side) keep the load side wiring shorter.

Don't forget to wire in 30 amp fuse,

ajfran3

I ended up just following the directions on the sheet exactly how they were but it's not turning on. I spliced the two wires coming from the fan into into one using a heat shrink butt connector then attached a 30 amp fuse and connected it to the orange wire on the relay. I attached the red wire to the pdc using a add a fuse putting it in the aux lmps position. I attached the ground to the chassis and ran the yellow wire to the cab and attach it to a switch and then ran a ground wire from the switch to the battery negative. I'm not using the green wire. What do you think is wrong

awg

I dont know what is wrong, but here is how to test it

The red wire should be connected directly to the battery or pdc (just run a bit of wire from battery + terminal and twist it onto your red wire

get the yellow wire and touch it onto this same junction (+12v)

Your fan should switch on (assuming it is correctly earthed and the fans work)

If it does, find out why the yellow wire is not getting triggered to switch the fan relay on

If it does not, you have some other fault

my next step would be to run wire direct from battery + to fan, bypassing relay, fan should start up

if it starts up, re-examine what you did

in any case, make sure your earth connections are good (the best way to do this is disconnect battery + lead and measure with multimeter between your fan ground screw and battery - terminal, should be very low resistance)

Saudade

You switch is grounded at both ends. The Yellow wire needs to to to a Key switched 12v source.

The way I read this, you have a 30a fuse from the PDC to the relay AND a 30a fuse from the relay to the fan? You don't need 2 fuses for the fans. The one on the red wire will do,

ajfran3

So I guess my problem is the switch with the yellow wire. I touched the yellow wire to the battery and it started right up. I want to only have it come on when I turn a switch though so how would I do that.

ajfran3

I added a 30 amp inline fuse where the orange wire is because in the diagram it says to have one between the fan and relay connection. I just added a fuse tap so that I can plug the red wire into the pdc. Should I add the red wire directly to the pdc instead of the place where I have it with the fuse tap

ajfran3

Dude you are the man. I was able to get it figured out and wired to a switch because of your suggestion. I really appreciate the help and the help of everyone else. Thank you