So far the fan has worked as it should with the new solenoid. The fan only comes on once all the coolant has reached about 200degF. That way its not fighting the thermostat. It comes on rarely, only on 75deg + days while in traffic and stays on for maybe 5 min at a time. The fan is pretty loud if standing outside the vehicle. I have it wired on high and one can feel air being sucked through the grill. My fan brackets utilize the old mechanical fan shroud mounts on the radiator. They are angled up to hold the weight of the fan while two zip ties hold the bottom tight on the radiator. I didnt have to drill a single hole in my explorer. I used existing holes for mounting the fan, controller, fuse block, solenoid and grounds.
My controller is mounted directly to left of the radiator out of sight. Solenoid and fuse block are mounted between the battery and fender. The only wire I had to extend was the fan power wire which went to the solenoid.
Here is the wiring diagram I used. I dug deep and ended up finding it on RPS.
8 gauge is not really necessary even for the MarkVIII fan. Its harder to work with so Id use 10 if I were to do it again. Instead of the Imperial Controller I used the Hayden one from O'Reileys(same thing). In place of the 75amp relay I went with a 200amp golf cart solenoid. My fuse block houses one 40 amp fuse and one 100 amp fuse. I used the closest diode RadioShack had to offer.
This is my controller thermometer location.
Hayden controller buried deep. Just enough room to access the temp adjust.
Fan ground next to battery tray. The wires tied up are for dual fan setups and AC wiring that I wont be using.
Here is my solenoid and fuse block. Keep in mind the solenoid body is grounded. Sand off the paint where its mounted. Red wire on the 40amp fuse powers the controller. Black wire on 100amp fuse powers the fan. One small solenoid post is grounded. The orange wire on the other small post is actually the one that would power the fan if the solenoid was not present. The orange is used to switch on the solenoid sending power to the fan. Diode is on output large post to ground. I painted my fuse cover black and have a black sack for the solenoid to keep them hidden and protected from dust. My signal wire for the controller is on my fuel pump fuse, however any hot 12V source will work.
Junkyard Mark VIII fan: $25
eBay Prestolite Solenoid 12V, 200 continuous amp, 4 pole: $30 shipped
eBay 100amp fuse pack: $2 shipped
RadioShack connectors, wiring, 40 amp fuse, on sale fuse block, diode: $15
Lowes 8 gauge 6ft: $3
O'Reileys Hayden Fan Controller: $36. Can also be found at Advance and Autozone under different names.
total: about $115
This is a good alternative to the pricey DC controllers. Most of the cheaper ones don't even support the Mark VIII fan. This fan will blow fuses and fry relays under 100amp. With a 200 continuous amp solenoid this system is overbuilt and should last the life of the vehicle. Is the e-fan conversion worth it? probably not, but I learned a lot at the expense of little cash.
