What is it?
The Casper's Electronics High Speed Fan Switch is designed not to
interfere with PCM control of the High Speed Fans. Three automotive grade sealed relays
are included which makes this unit completely weather resistant. OEM connectors at the fan
are included as well. This unit, as with all Casper's Electronics products, is entirely
plug in. There are NO WIRES TO CUT! An LED indicates the status of the fan control.
1/4" Nut Driver
Short Flat Blade Screwdriver (For removing OEM connector clip)
1/8" Drill Bit
Fish Wire/ 12 or 14 Gauge Solid Wire (For feeding line through
grommet on firewall)
1. With engine off, and cool
2. Gently unplug the two connectors from the fan housing (see
picture above). **This may be easier to do from under the car**
3. Plug the factory connectors into the harness and the new
connectors into the fan housing.
4. Using the center punch, mark and drill the holes for mounting
the relays. I did one relay at a time to get the spacing right (see above picture).
5. Securely mount the relays to the fender wall in front of the
coolant tank (see picture above).
6. Safely route the wiring harness in front of the battery and
around airbox to the Auxiliary Fuse Box by the driver side strut tower.
7. Unbolt the relay that is mounted to the fender wall and
reattach with the ground wire (see picture above).
8. Using a pair of pliers, remove the plastic retaining
clip above the driver foot well area and remove the carpeted panel.
9. Using a fish wire, push through the rubber grommet into
the engine compartment. You may need to poke a hole in the rubber with a
10. Attach the connector end of the switch wire to your
fish line and pull through the fire wall into the engine compartment (see picture above).
11. Attach the switch connector to the fan connector on the
12. Using a 7mm socket, remove the retaining bolt holding
the positive lead to the fuse box.
13. Slip the red wire with ring over the post and replace
the bolt (see picture above)
14. Drill and mount the switch and LED in the engine
compartment. You may need to cut the leads on the LED to mount the LED. Just
solder or crimp
the wires back together
and wrap with electrical tape.
It's fairly straight forward. When you turn the switch on,
the LED will start to flash. ***YOU CANNOT CHANGE THE LED*** if you try and put a
different LED on the switch, it will burn up. ***Keep in mind that this harness
will run without the key in the ignition, so you have the potential of leaving it running
and causing a dead battery. A safe running time on battery alone would be no more
than 15-20 minutes.