radiator fans

[Slide infantry]

Okay so i had my whole car rewired with a new chassis harness and an arc 8000 switch panel. Car has been running fine till the other day i left it running and notice it started over heating. So i find out the fans arnt working. They're the mishimoto dual fan shroud so i start looking around. So the fuse on the arc 8000 switch panel is blown, i switch it with another 30amp and as soon as i hit the fan switch it blows the fuse. I checked the relay on the same fuse box and it seems to be okay. so i tested the fans on a battery and they turn on. Does that mean they still work or do they turn on because its directly off power and ground. I also left the fans disconnected and hit the fan switch and it still blew the fuse instantly. If any of you guys can think of anything i would highly appreciated. I am really not trying to undo the harness if i don't have too.:confused::confused::confused:

[Tyler_240]

I've had good success with this configuration. Fans can pull some amps, so I would suggest using a minimum of 14g wire. Fans can be grounded to the chassis, I used the radiator hold-down bracket location for mine.

Using a 40-Amp Relay, Pin 30 & Pin 86 should be wired together and run to the battery. Use a 30-amp inline fuse near the battery.

Pin 85 is your (-) switched ground, if you have a fan switch, you could use that and ground the other end of the switch.

Pin 87 is a +12v signal, so that hooks to the fan's (+) wire. Personally, I used two 40-Amp relays on an altima fan setup with zero problems, so you may want to consider using a relay for each fan.

You would simply wire both Pin 85 & Pin 85 together on each relay, and then run that to your (-) switched ground.

Pin 87a is unused

[williamjbrown93]

I'm assuming you have a short somewhere in the circuit after the switch before the fans. One of the power wires have to be going to ground in order for the fuse to blow with the fans disconnected. The fans are supposed to be completing the circuit. We know the fans are good because you can power them directly off the battery without frying wires and since you say the fuse blows with the fans disconnected. Check for pinched wires, worn wire insulation, ect. If you are using the switch as a positive trigger for the relay and if you have a multimeter you can test continuity from the output of the switch to ground. If there is continuity it means that wire is shorting to ground. That's not all the info but should at least be able to help you isolate the issue a bit.