Mark VIII fan install
- Thread starter 85_SS
- Start date
- Status
Do you still have the ECM in the car? The wire you need is already in the ECM harness in your engine compartment.
It's interesting you have a true 2-speed Mark VIII fan....I have yet to find one....all of them regardless of the inspection plug are single speed. Ford used a series of power transistors in their VSF controller which varied the specs in several steps. If you ground the black lead and apply power to one terminal and then the other, you should be able to tell the difference in fan speed based on that-no change means its single speed no matter what else. I gave up on the relays for it as a result and instead I have been building resistor harnesses where each speed is resistored out to give you up to 4 fan speeds if desired....still relay activated through the use of temp switches, manual override and AC use.
Now, the RF24 fans are similar in design and while not quite as stout are still better than anything aftermarket-and for those I use 2-speed relays to simplify wiring. Dustin, I remember the DC Controls and Spal fiasco a few years back-I have not gone back to a controller since then either. If anyone needs help with the circuit wiring, let me.know, I have excellent harnesses to simplify wiring for these fans....some of the connectors and weatherpak terminations require the right tooling but some things you can build yourself.
Now, the RF24 fans are similar in design and while not quite as stout are still better than anything aftermarket-and for those I use 2-speed relays to simplify wiring. Dustin, I remember the DC Controls and Spal fiasco a few years back-I have not gone back to a controller since then either. If anyone needs help with the circuit wiring, let me.know, I have excellent harnesses to simplify wiring for these fans....some of the connectors and weatherpak terminations require the right tooling but some things you can build yourself.
gmachinzz said:
Not to steal the thread, but I have a two speed, absolutely mint Mark VIII fan for sale. Bought it for my Malibu, but it got destroyed BEFORE I had a chance to put it in.
Make sure you verify the terminals to make certain it is 2-speed. Ford did not use it that way in the Lincoln's.....Ford model cars yes but Lincoln's-no. This was the reason for a progressive controller....vary the single, high speed feature of the fan to where you want to run it. A traditional 2-speed controller won't work with them. Now, if there are 2 speed Mark VIII fans out there that would be a rarity imo. Not to say there isn't but knowing how the factory Lincoln fans were controlled I would have to doubt it.
Here's a thread on the subject over at pro-touring (where you seem to have acknowledged/seen two speed fans at that time?):
http://www.pro-touring.com/showthread.p ... k-VIII-fan
What I've always understood/read is that the earlier fans were a true two speed type and the later models went to variable speed, controled by the ECM. This would explain the "dummy" terminal on the single speed fans (they are actually jumpered together IIRC) and makes sense. I can only assume Ford kept the extra fan terminal there so that you could actually put the newer fan in an older car (ie. backwards compatible as a replacement). It would still be functional, although the low speed functionality of course removed due to the fact the "low" terminal is simply jumpered with the high (ie. whether the car called for low or high, the fan runs on high only).
http://www.pro-touring.com/showthread.p ... k-VIII-fan
What I've always understood/read is that the earlier fans were a true two speed type and the later models went to variable speed, controled by the ECM. This would explain the "dummy" terminal on the single speed fans (they are actually jumpered together IIRC) and makes sense. I can only assume Ford kept the extra fan terminal there so that you could actually put the newer fan in an older car (ie. backwards compatible as a replacement). It would still be functional, although the low speed functionality of course removed due to the fact the "low" terminal is simply jumpered with the high (ie. whether the car called for low or high, the fan runs on high only).
Yep-but it would have been the early 1993 MARK VIII fans.....similar to the Tbirds in designs however the fan blade itself mounts differently. I had seen where people had 2- speed mark VIII fans but everyone I found...even new at the time were single speed. Then I had the local dealer pull up a fan diagram for the Mark VIII fans and what I received was a mini ECM of sorts that controlled the fan at several speeds based on TPS, AC useage, CTS, VSS, etc. and the fans VFS varied the speed through a series of transistors....talk about over-engineered! What's odd is that the T-Bird fans look identical and they are 2-speed. I guess Lincoln had to have a complicated way of doing it. So at the time everyone was using the Mark VIII as a high speed fan and dialing the speed down by way of pulse width, etc. Now of course the Mark VIII fans from Motorcraft have gone discontinued and the Chinese replacements I know nothing about other than I'm sure they aren't even as good a quality as a junkyard OEM one imo.
That's what I have come to believe. A simple test is to jump the fan terminals directly off the battery to tell for sure. You cant at least on the Motorcraft fans, run power on both the low speed and high speed-you have to run it on either speed but not both, so a simple test can verify the two speeds.
- Status
