are the mark 8 fans 2 or 3 wire fans.....i think i bought a Mark 8 or maybe a Contenental fan on Ebay ($50 delivered), but it only has 2 wires.....and I was readingthat a capacitor might need to be wired in to suppress a voltage spike due to a rather large initial draw when turning on. Anybody wire theirs up with one?

What do you use for a temp sensor (and where did you install it) to turn on the fan?

Anybody have pics of thier trimmed fan?

I also got an electric fan for a 3.8 Ford Taurus which is suppose to due the job as well...some Jeep owners use it and it is also used for the 5.0 Mustang.....not as much of an initial current draw though.


TIA

 

anybody have pics of their Mark 8 Installed?

 

I do, I'll try and get em up here shortly. The Mark VIII fans have 3 wires.One Ground,one 12V+ for low, andone 12V+ for high.

 

Here is a few pics of mine installed. Eventually I am going to fab some mounting brackets, but for now, I just used those push-through type fasteners. They work just fine. Oh and don't mind the half ripped flap on top of the radiator, it bugs the crap outta me, I just havn't gotten around to replacing it.

 

Hey rtkota....Are you running a Capicator to suppress the voltage spike from the initial turn on of the fan?

Nice supercharger by the way.....did you have to beef up the crank to take the extra power?


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ohhh a r/t supercharged....*drools* gas alone in a stock r/t is killin me haha cant imagine a supercharged one...but yea that fan looks nice and there fairly cheap...i just dont know if i can wire it, i have like no wiring knowledge at all

 

Yeah....same here. I thought it would be really easy, but after reading this thread, i am thinking otherwise! lol
Man....that supercharged RT is sweet. Haulin' *** is probably an understatement! Fan looks really nice too.

 

ha yea...like excuse for being dumb and to its 5:30am in the morning again but relays are just basically bridges that u can open and close in the circuit right?..sorry im just tryin to picture how to wire this up haha...then again i should stop doin all my thinkin at 5 in the morning


*edit* so the mark 8 will be louder then the clutch fan when its on high?

 

yes, relays are like bridges with a high currentunswitched positive power supply on 1 end and the controlled device on the other. There are 2 moreadditional wires low current(1 positive and 1 negative). When the low current switched power is applied to the relay, it will energize the relay(due to the negative going to ground constantly). When the relay is energized, the "bridge" closes and lets the highcurrent flow through it to the device....

low current controls a high current which prevents switch failure from excessive initial arching.

Then of course, there are other things that could be added into the circuit......capacitor, thermostatic switch, sensors, and indicator lights.

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I did no use a capacitor and have had no problems as of yet. When an electric motor starts, it can take up to 3 times it's running amperage, just for a split second, to get it moving. So on high, the fan could draw up to 90A to start. Relays are only rated at 30-40A. So you will most likely be replacing relays every once in a while due to this. But it's not gonna be every other day. More like every year or every other year. Maybe longer. If you can afford it, get the fan controller. It basically supresses the fans inital start-up spike, and controls the fans speed automatically depending on the tempurature of the truck. So the need for a HI/LOW switch isnt necessary.

Here is a diagram of how mine is wired. I havnt had to replace a relay yet, and the thing works flawlessly.




Here is a few notes:

- The relays are 30A SPDT (Single Pole, Double Throw) Relays
- The layout is exactly what you would see when looking at the bottom of the relay in real life.
- Terminals "86" and "85" can be used interchangably as (+) and (-). They are the coils, low current power. The coil doesnt have a designated (+) or (-), so it doesnt matter which you use for either.
- Terminal "87A" on the first relay doesnt get used.
- The "Fatter" wires on the diagram should the 10AWG wire, the smaller ones can be 12-14AWG wire.