Ford Contour Fans w/ Spal Programmable Fan Controller Conversion ...
After 11 years and some 400,000 miles it appears that my factory fan clutch is on it's last leg. A dead fan clutch is definitely something that will leave you stranded on the side of the road so this was immediately bumped to the top of my 'broke stuff to fix' list. I spent an hour or two checking prices at the dealerships, local auto parts stores and on the Web and quickly decided that instead of installing a new OEM clutch or a cheap Chinese replacement I'd rather spend my money on a conversion to an electric cooling fan setup.
Electric fan conversions aren't exactly new or 'bleeding edge'. My first conversion was my '68 Pontiac Firebird some 20 years or so ago after reaching the point of being completely fed up with replacing expensive fan clutches every couple of years. The three most common reasons to replace the factory clutch fan assembly with an electric fan assembly are ...
• can't fit a mechanical fan or fan clutch in the available space
• reduce parasitic HP loss as a competitive advantage in racing
• increase gas mileage
Strangely enough, 'sick of replacing expensive fan clutches' isn't a top contender for the list. Most likely that's because factory replacement fan clutches usually last at least five years before their performance starts to degrade. Even then, it may be years later before the clutch is operating poorly enough that the engine overheats and leaves the driver stranded. Since most people don't own a car more than five years its unlikely that they'd ever get to the point of having to replace a fan clutch let alone replace it more than once.
I, on the other hand keep my vehicles forever, truly despise clutch fans and have little good to say about them. To be fair, though, I have to admit that a half dead clutch fan typically pulls more air at highways speeds than any electric fan set up and clutch fans do not ever just 'die' over night. If you're sitting on the side of the road because the clutch on the fan quit working - well, there's plenty of tell-tail symptoms to alert a driver long before that point is reached. Not so with electronic components and electric fans. So, I guess clutch fans do have one or two good points.
Anyway, my primary reasons for replacing the factory mechanical clutch fan with an electric fan setup:
- the existing clutch was already heading south so I had to spend some amount of money anyway
- a fan clutch set up still sucks more power from an engine than turning the alternator, even a higher amperage alternator
- for water crossings I wanted to be able to turn the 'fan' off
- for seven months out of the year I do not need freezing cold air blowing on the engine while waiting for it to warm up
- I wanted to take the wear and tear of a heavy spinning fan/clutch assembly off the nose of the water pump
- mechanical fans and clutch fans don't move a lot of air at low engine RPMs; a problem when crawling in 105+ degree temperatures
- a new replacement fan motor was less than $50; the entire new dual fan assembly is less than $150
Most of the above reasons are pretty self-explanatory. Anyone that's driven a crawler out in Moab or SoCal in the middle of the summer knows what it's like with the heat reflecting off the rock and sand and sucking the fan into the radiator during a deep water crossing is no fun either. Most people don't realize, however, how much wear and tear a clutch fan assembly puts on a water pump when it starts going out of balance or how much longer it takes an engine to warm up in 0 degree weather with the fan blowing freezing cold air into the engine bay. Nor do most people realize that it generally takes from 8 to 15 horsepower to turn a fan or fan/clutch at highway speeds yet only takes about 1 to 1.5 horsepower to turn an alternator. Maybe this isn't significant to people with 450 CID engines producing 400+ horsepower, but to those of us with V6's cranking out a piddling 184 horsepower (on a good day) - 5 or 10 horsepower is NOTICEABLE!
So, after doing a ton of research all over the 'Net and talking to a few people that do conversions like this on a regular basis I settled on the factory Ford Contour V6 dual fan assembly and the Spal FAN-PWM-V3 controller with the FRH relay harness to control the second fan. The Ford Contour dual fan assembly is commonly avaible both new and in junk yards for a reasonable price - $30 at the salvage yard and $109 new on the 'Net - and is supposed to flow 3400 CFM while only pulling a maximum of 36 amps. The new V3 Spal controller will handle - ONE - fan up to 30 amps and a SECOND fan using the FRH relay add-on kit so I didn't have to worry about too much fan for the controller. One of the primary reasons for using the Spal controller was its built-in variable speed function for the primary fan; adjusting the speed from 50%-100% using Pulse Width Modulation (PWM). Not only does this not run the primary fan at full speed all the time even when not needed it also allows the primary fan to be spun up gradually thereby not incurring the amperage draw 'spike' typical with 100% on/100% off control systems. This is non-trivial; fans can draw up to double their constant amperage draw at start-up. A good example of this is the Lincoln Mark VIII which can pull upwards of 90-95 amps at start-up but typically runs around 30-40 on low and 40-50 amps on high.
The other primary reason to use the Spal is that it was supposed to allow the usage of the factory Engine Coolant Temperature (ECT) sensor. This is NOT to be confused with the dash temperature gauge sensor or the idiot light sensor. This is the sensor that the Engine Computer Module (ECM) uses in controlling the fuel system. My theory - after having dealt with the 'stick the sensor through the radiator' and the 'stick the sensor in the hose and clamp the hose back down' sensors - was that possibly pulling that info directly from the factory sensor was probably going to give me the most accurate and reliable readings. I also figured that if the factory sensor didn't cut it that installing Spal's FAN-PWM-TS temperature sensor wouldn't be that big a deal - especially since the harness for the sensor was already included in the kit. There are a number of in-hose adapters with the 3/8" NPT port for around $30.
I ordered the Spal controller, add-on relay kit and the Contour Fan assembly. Both showed up in good order and everything was as it should be. Before installing the controller, relay and fan assembly I would need some additional parts and pieces. The Spal controller and relay kits come with everything you could possibly need for a standard installation connecting to their fan(s). Unfortunately, I wasn't using their fan(s) and I wanted this to be as clean, compact, durable and water tight as possible and I wanted it to be removable with no more hassle than the stock radiator, shroud and fan assembly. I ALSO didn't want anyone else that might have to work with those parts to need a PHD in 'Stupid Backyard Engineering Tricks'.
The first thing - or 'things', actually - was the factory fan relay harness. Napa sells the fan motor plugs which I kinda needed - for about $28 dollars each. That was good for a chuckle - although I think my hysterical giggling slightly ticked off the counter person. Off to the local 'pick-a-part' yard where they had half a dozen Contours in various states of demolished. One complete like new fan harness - $5. I even found one that had already been removed and was waiting for me draped across a half dismantled engine. Sweet! The other pieces I wanted were the heavy power connectors for the factory fan harness. The fan harness comes with one end; its mate just needed to be sniped off the engine harness. One more Contour - in MUCH worse shape in the front; I didn't want to destroy a GOOD harness if possible just for a connector - gave me the other complete male/female power connector. These connectors are great! They're watertight and since they're designed for the full amperage of BOTH fans running through one connector they're plenty heavy enough for one fan per connector; both pair of connectors were $2. So, between the Spal controller, relay kit and the factory harness and two connector pairs I had all the wiring I'd need for the entire project.
The next stop was a favorite store here in south Denver that specializes in automotive pieces and miscellaneous parts, connectors, trim, insulation, weather striping, etc. There were a couple things I wanted that the fan assembly didn't come with. I wanted the press-in clips for holding plastic wiring conduit, the plastic wiring conduit and most importantly I wanted some U channel weather striping to run along the edge of the fan shroud where it would sit against the radiator core. They had the weather striping in the EXACT size I needed - sold by the foot; I ended up using about 7' but bought 8' just in case - as well as the half-dozen clips and eight feet of conduit; all for a total of about $8. Unfortunately, suffering from a brain fart, I forgot to get heat-shrink tubing while I was there.
One last trip to Napa and Autozone yielded up a on/off rocker switch with LED, heat-shrink tubing, 18-guage butt-connectors, a blade type fuse tap and a box of 5-amp blade fuses. I had already decided to solder and heat-shrink all the joints except for the couple connections inside the cab. Colorado uses some nasty de-icer here in the winter that destroys bare wiring and connectors in a season or two and I have no intentions of rewiring this every spring. Butane for my solder torch, my solder torch and lots of solder were already stashed in my 'emergency stuff' tub in the back of the truck as well as my OBD-II scanner - to read the ECT sensor temp - so I was pretty much ready to go.
Complete write-up and pictures comming soon!