Recently, the fan clutch on my ’85 GT decided to cash in and retire…a sticky situation in traffic for sure. As with most projects Ford-related, I saw this as an opportunity to do something different. In this case I would go the electric fan route. Lousy, cheap fans and controllers in the past had left a bad taste in my mouth, not to mention left me on the side of the road a time or two. I decided to do a little research and choose a good OE fan, and more important (and subject of this article) a good quality controller.
FAL vs DCC: Fan Controller Reviews
A quick note on my fan choice
I had initially thought I would end up with a Taurus fan, but after further research eventually chose a Contour type dual fan. The shroud fitment would be close to perfect, and the amp-draw would be less while flowing plenty of air. I picked up a 2001 Cougar fan (same as 95-00 Contour/Mystique) at the local yard for $50.
When you’re done laughing at my methodology, note that the trusty old Sunpro is indicating just over 20 amps from the Contour fans. This is the stabilized amperage with 12 volts to the high-speed wire.
The next step was to choose a controller. There are plenty of choices out there, and I had gone with the Contour fan in anticipation of using a relay-based controller and not have to worry so much about the amp spikes when the fan “kicks on.” In the end, however, I elected to use a variable speed controller to spin the two 12” fans. I actually ended up testing 2 different popular types, and this article will compare them and talk about the basic concepts of this type of controller.
The first popular controller I ran was a Flex-a-Lite VSC (for variable speed control) part # 31165. It should be noted that there is also a #33054 which is supposedly rated for 40+ amps, instead of the 30 amp limit of the one I ordered. Since the Contour fan puts out much less than 30 amps, I wasn’t worried about it.
The Flex-a-Lite (FAL) VSC. The 31165 kit has a lot of “stuff” with it in the way of wiring and terminals. This is just like the one I received and is the newer design, as the 10- gauge fan wires are molded into the controller, rather than on spade terminals.
The VSC boasts some features that go above and beyond the $30 parts store fan controller. First, it uses what FAL calls a “soft start” feature. This is really the major boon to these types of controllers. Instead of a relay that “kicks” the fan on 100% at a predetermined temperature setting, the variable speed (and delta current) technology adds current at a slower rate and allows the fan to “ramp up” rather than “kick on.” This “kick” is what causes the amp spikes of anywhere from 60 to over 100 amps when the fan is first gaining its inertia from a stop. Let’s face it, a lot of the OE fans that really do the job aren’t putting out 10 amps like some of these aftermarket units.
Here is the VSC mounted to the Contour fan. I like the GM-style “weatherpack” terminals to neaten-up any aftermarket wiring. Here I used a 4-pin connector (top right) for the ignition, a/c, and fan power/ground. This will ease service removal of the fan or radiator and fan combined.
In the case of the FAL VSC, the fan first comes on at 60% when the set temperature is reached on the probe. The controller then gradually increases the current to power the fan to 100% as the temperature climbs over the next 10º. With the air conditioning compressor wire connected, the fan will automatically run at 60% when the a/c is on, unless probe temperature determines a higher speed is needed. If an ignition-only source is connected, the VSC will wait 5 seconds from the time the key is on before it powers the fan. This is supposed to give you time to start the car without too much load on the system. The fan will also run up to 30 seconds after the ignition is shut off when the controller deems it necessary. The FAL VSC also has terminals for both “on” and “off” manual switch overrides.
I mounted the VSC on the shroud with spacers below it to keep the unit cooler. My major gripe with mounting the FAL model is I’m not a big fan of the plastic crimp terminals sticking out. In addition, the 10-gauge fan wires stick out the top. With that, it’s not a very low-profile setup as you can see. The wiring sticks out farther than the fan itself…but all in all it’s not bad.
O P E R A T I O N
On the initial trial of the VSC controller, I noticed that once the engine got up to temp (180º thermostat) at idle, the fans cycled on for about 5 seconds, then off for 10. It repeated this cycle pretty consistently for about 10 minutes in the driveway before I shut it down. It maintained about 195º or so during this time with ambient temps in the upper 80’s. I figured this was because the probe was in a part of the radiator that was covered by the shroud. When the probe got hot, the fans came on and subsequently cooled the probe enough that it shut back off, then heated right back up…rinse, repeat.
In the case of the Contour fans, the shroud covers so much that there really isn’t much space to shove a probe through the radiator outside of the shroud. On a side note, when I ran the a/c at idle the temps ran a little cooler. This is due to the fact that the fans are running at 60% all the time, and again speaks to how much air the Contour fans move.
Here is where the probe ended up. I reluctantly modified my brackets to raise the shroud up on the radiator about ½“ so that about 1 inch (2 cores) is exposed on the bottom. This allowed me to push the probe into the radiator somewhere outside the shroud, but still be exposed to hotter coolant from the inlet tank.
Having relocated the temp probe as shown in the picture, I was ready for another test day. I did mixed city and low speed highway driving on a humid 90º day. The first leg of the trip would be with a/c blasting. The car ran a steady 190-195º on the highway portion of the drive. When I got into town, I hit a long stoplight. I watched the temp climb a little, but it never got above 200º as I sat out the light…a/c blowing.
I have no way of knowing what % the fans were at, or if they ever got above the 60% minimum with the air on. Once I got moving again, the temps came back down a little. For the return leg, I suffered through having the a/c off to see how well the controller really controlled. It was disappointing. I pulled into a parking lot after a good little highway cruise. Once again, the controller cycled the fans on and off for about 5 seconds. I watched the temp climb from 195º to 205º…a full 10º.
The fans never increased % or ran continuously, just sat there cycling on and off as the temps climbed. A little stop and go driving got me back to the garage, but the temps got close to 210º until I hit speed again and let the moving air do the work. I imagine had I let it sit long enough, the car would have overheated, all the while having a perfectly good high-flowing fan sitting right there giving little bursts of air on an off. I removed the FAL VSC and returned it to its packaging.
Brian Baskin’s Delta Current Control has been around awhile now. One visit to his website Welcome to Delta Current Control
, along with a good afternoon of reading through his technical data, and you quickly realize that he just may know what he’s talking about. Ever since I heard about DCC, I have wanted to get my hands on this controller as part of my quest for reliable cooling. It took 6 weeks from the time I sent the Paypal to the time it landed in my mailbox. You heard me right, 6 weeks. Having done what research I could, including the usual Internet lore, I was actually expecting this. Brian builds these things himself, and since I ordered in the early summer, he had his plate full of orders I’m sure.
The Delta unit I ordered was the FK-35, “35” being the DCC designation for amp rating of the controller. If your fan draws a steady-state 35 amps or less, you’re good to go. Even a quick glance shows you that it’s a well made unit. The case is aluminum, not plastic. The primary wiring utilizes posts/ring terminals rather than spade types. The FK-35 is slimmer in profile, but slightly wider than the VSC, so I had to mount it on a larger part of the shroud, on the lower driver’s side.
Here’s the DCC FK-35 mounted to the shroud.. Notice the lower-profile. The case is slimmer and the post terminals allow wiring to protrude sideways, not out the top of the controller.
Unlike its Flex-a-Lite contemporary, the DCC controller will run at any output, not just 60-100%. Instead of an infinite dial control, the DCC is factory set to work with a 180º thermostat. Any other settings are accomplished using jumpers on specific pins (visible in the picture above). There’s even a “under drive” jumper setting that will run the fan at 10% whenever the key is on for those cars running u/d pulleys.
The jumpers allow you to adjust the temperature at 7º and 14º increments either side of 180º and the instructions have a chart detailing which jumper settings give you what operating temp. The probe itself is a special design. Like the FAL, the probe mounts in the radiator fins. The difference is the DCC probe is a stubbier design and is insulated. The specially designed probe allegedly doesn’t have the problem of temperature fluctuation whenever air is cooling the radiator fins.
O P E R A T I O N
Test 1 in the driveway was a short one. I started the car and switched on the a/c. Nothing. I waited for the engine to get up to operating temp and watched the temps steadily rise. The fans never moved. Test 1 over. I emailed Brain, who quickly got back to me. I’m always happy when I learn something new, and as it turns out the Contour fan uses a low-impedance motor. The DCC, having internal short/fault protections, interprets this characteristic of the Contour fan as such and won’t power the fan. Brain mailed me a 1.5ks filter to install across the ground and power terminals in order to solve the issue.
Test 2 started with the fan mounted as it was with the FAL VSC, with 2 cores showing under the shroud. I mounted the probe near the outlet tank through the radiator fins as depicted in the instructions, and below the shroud between the bottom 2 cores. With the engine running I tried the a/c. The fans spooled up to what I presume is the DCC’s 50% “a/c on” setting. I shut the a/c back off and waited. The temps came up as usual, but the AutoMeter was reading 210º before the fans came on.
I noticed the fans were very quiet…noticeably quieter than the 50% setting with the a/c, so the fans were running at some undetermined lower speed. The temp stayed rock-steady on 210º. I decided to move the probe to a higher location, which, in the case of the Contour fan was through a sizable hole that once housed the stock high/low speed resistor. I also set the jumpers for 173º in hopes of correcting the running temperature.
Test 3 was an “incomplete” success…I’ll explain.
The changes I made brought the fans on at about 185-190º on the AutoMeter. When idling, driving, a/c on or off, didn’t matter—the temps were rock steady there. I emailed a report back to Brian, who quickly replied. He thought the insulated probe wasn’t making good enough contact with the radiator fins, and that I should not need the cooler jumper settings. Brian suggested that I should re-check how well the probe was mounted. Back to the garage I went.
Enter test 4. I did a little more bracket modification so the fan now sat lower on the radiator. I was much more careful with the mounting of the sensing probe this time. I used a flat head screwdriver to make a nice home for it between the fins so as to make good contact. I still mounted it through the big hole in the shroud as before. I also removed the jumpers to reset the unit to the stock 180º setting. This time it was a complete
success. City, highway, parked, a/c on or off—the gauge stayed steady at 190º or so, which is perfect for my thermostat. Ambient temps were in the mid to upper ‘80s that day as well.
Either this gauge is stuck, or the DCC works like a charm. This is where the needle stays after the engine warms up at idle. This shot was taken in line at the bank teller. At highway speeds, it comes down about 5º.
As a result of the testing above, I have to endorse the DCC controller. The engine temps don’t fluctuate at all and I never saw the fans cycle on and off…it just works. As for the Flex-a-lite VSC, I sent it back to Summit
after the determination that I had a defective unit. The fact that it ran at 60% with the a/c on tells me it wasn’t any kind of fault protection response like I saw in the FK-35. Also, no matter where the probe was mounted in the radiator, it exhibited the same behavior and poorly controlled the temperatures.
I’m not a big fan of the push-through radiator probes that seem so commonplace in the aftermarket. I think the direct thread-in coolant sensor allows for a much more error-free fan controller. How many factory setups do you see with probes jammed into the radiator? However, the insulated design of the DCC probe seems to mitigate some issues much better than the bare probes with a rubber nipple stuck on the end. In all fairness, Flex-a-lite does offer a thread-in coolant sensor for the VSC controller. It may very well be a quality unit that more reliably operates the fan than the one that showed up in my garage.
I urge you to take this info for what it’s worth. I know there are several good Flex-a-lite controllers out there that “work just fine” and I’m sure I’ll hear about them as well. As with everything else, I tend to get the 1 out of 100 defects sent to my door, and I feel I’m duty-bound to report that. Keep in mind that among my standards for “reliability” in any
product, one biggie is that it not be defective out of the box. Overall, I hope that anyone interested in putting an electric fan on their car found at least one or two tidbits of this information useful. My apologies if I didn’t delve more into the inner workings of this technology. I got my electrical engineering degree out of one of those claw-crane thingy’s at the arcade.
Author’s Note: SPAL also makes their version of a variable controller called the PWM (pulse-width modulation). This version supposedly allows use of a car’s stock temperature sender. Unfortunately, I did not get the opportunity to test this unit during the other evaluations.