Mark VIII Fan and Custom Controller

[TonyHuntimer]

I have been really happy with the installation of my new Lincoln Mark VIII fan.
http://www.racehome.com/images/april04/mark8fan.jpg



The MARK VIII fan and 55GPM Meziere electric water pump work really well. Sitting in traffic in 98degree weather last week... The car ran at 175 to 200 all the time. It runs the same in the morning when it's 68 degrees outside. I am not worried it will overheat at all!

I have it hooked up with a 75AMP Bosch relay. When the fan kicks on, the charging system gets a shock! The gauge runs up and down a lot.


I found a new product I'm going to install. I found them by accident. I like getting info from a happy customer, he sent me to this place sells a controller that supposedly works really well on controlling the HUGE Mark VIII fan and its AMP draw:
http://www.dccontrol.com

It helps ramp the fan motor, rather than SHOCK the charging system. It also helps even out the temperature in the cooling system. Rather than having it HOT.... COLD.... HOT.... Which is not great for the engine. It's more gradual.

Just sharing.

Tony Huntimer
RaceHome.com

[68LSS1]

So the 60amp unit will be enough (that's the bigger of the two they offer)?

[TonyHuntimer]

Aparently the FK-35 works fine with the Mark VIII fan. Some people like to put one of the standard ISO relays on the Mark VIII fan. They are rated at 40/50 Amps. This sounds like a good thing... Right? Wrong. Unfortunately, when the fan does not have a controller to help it "ramp" up slowly, when the fan kicks on, there is upto a 100AMP spike! That is a good way to smoke your wiring harness.

The DCControl.com controller removes the spike and controls the fan without all the extra wiring usually needed to wire the Mark VIII fan "the right way".

Tony Huntimer
RaceHome.com

[gmachinz]

Hey Tony-thanks for sharing-I'm going to look into that controller for my fan. Initially I planned on running a 70-amp Hella realy with a 50-amp fuse and 8-gauge Monster Cable +12v supply wire to it. I don't think I would have a terrible spike problem, but I'd rather be excessive on the side of safety anyway. Thanks again! -Jabin

[derekf]

Good find. I think my shopping list just grew a little.

[Midwest Performance]

I have been looking into one of these units why doesn't someone set up a discount or a group buy? I was thinking of contacting them but I can't seem to find the time.


Kevin

[CarlC]

Is there a way to use a treaded sending unit instead of the fin-mounted thermostat?

[TurboLark]

Just some info for you guys with the M8 fans. I had one in my 88GT mustang a few years ago. I ran a dual 30amp relay setup from an old Product Engineering fuel pump. I also installed a 130amp alternator. My guage never ever even flickered when the fan came one. Make sure the alternator is rated high enough, and use a large(4g) feed cable to help out.

[gmachinz]

I'm thinking I wouldn't have problems with just running a HD relay and a 50-amp fuse and an 8-gauge power wire BUT-you could have an alternator overcharging to 200-amps or have it undercharging at 25-amps and the voltage could still remain the same, so the gauge mostly likely won't give you an indication of how many amps your charging system is putting out-merely just the amount of voltage it's operating at. For example, I had someone who thought they had a bad battery because their car would not start and their gauge always read 12.5-13 volts. Well, using an ARBST type machine I found out that the alternator was cranking out a max of 225-amps under a full load @ 2000 RPM while the voltage reading was a consistent 14.10V from the regulator. I think the DCControl is something worth trying out-the way I see it is like this: sure, you might not ever see a high enough voltage spike to cause any damage BUT-if it did happen, what could the results be? It's not a chance I want to take I'll tell you that. Preventative safety is what I call it. -Jabin

[Charley Lillard]

The Red Witch has had a Mark 8 fan on it since 1996 ? I think I have about 21000 miles on it now and the fan has been great. The Mark 8 fan is used in a production car. Does the production car use a device like is being discussed here ? It sounds like a neat piece but is it needed ? Just my thoughts.

[gmachinz]

Charles, I think it would be a great upgrade-here is a quote I have from the service manual for a Mark Vlll-1997.

"PCM determines when fan operation is required by monitoring coolant temperature, vehicle speed and air conditioning status. When operation is required, PCM signals VLCM to turn on fan to desired speed."

This doesn't actually point to a voltage control, but maybe the computer controls it along with fan speed. Thoughts, anyone? -Jabin