TheRepairMan

Well guys, I promised I was going to do this mod. So I finally got it done. A warning ahead... this will be a pretty long write up, and photo intense. And, here's a link to a file from Derale Performance Products you all need to read along with my instructions if you are considering this cooling fan mod to any vehicle. http://inet.derale.com/clientdocs/1_321.pdf

I had originally planned to do it during the timing chain job, but since I use the truck almost daily I decided to break them up into two jobs. Okay, first off, this is a 94 D21 2.4, std. trans, 2wd with AC, and just over 106,000 miles on the clock. No other particular concerns ...in other words, I'm not doing this mod to try to repair a problem with the truck, just to make some improvements in the heating and cooling systems. It may even just be a wash, but it seems nearly everything built has an electric fan on it now to make it more efficient, so why not our trucks, if we want.

There are pros and cons I guess to having this system take the place of your stock mechanical fan and fan clutch, so I'm not going to tell anyone it's worth the time, money, effort, or risk ...but I don't mind being the test rat. I'll be looking for better cold weather warm up (more interior heat sooner), better fuel mileage, and a slightly cooler running engine during hotter seasons. I'll report my long term findings back here as the miles add up.

Here goes ...the first thing was just to remove the 4 stock cooling fan nuts and store the old fan away.Next, the upper radiator hose at the radiator along with four screws that hold the fan shroud on to the radiator.

Aligning the new 16" cooling fan into position in the shroud was easy enough, so I drilled four holes and bolted it down. I had to cut a small relief in the lower section of the fan shroud for the cooling fan wire and connector.

Fan and radiator shroud removed.


I chose to remove the fan old stock fan mounting studs and replace them with some stainless bolts and lock washers. It already looks cooler!



Here's the new fan mounted in the shroud (just sitting up in the truck bed for photo purposes). This is the engine side. I decided against attaching the fan directly to the radiator to prevent any unwanted stress on the core tubes from the weight or any vibration that might be transfered. This was the best choice.


Here's the radiator side.


And, with the new fan/shroud assy. mounted to the radiator. If you look closely you can see there's about 1/2" clearance between the fan motor and the waterpump hub and pulley. That's more than enough.




I'll follow up with more details as I have time. The next steps are installing the adjustable electric fan controller.

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1994 D21 2.4, 2wd, 5spd XE

SPEEDO

I have been wanting to do that to mine for a long time... I like the way you are doing it, clean install!

TheRepairMan

Thanks! So far so good.

Here's a pic of the bottom of the electric adjustable cooling fan controller. Connecting everything was actually easier than installing the aftermarket stereo. Note there are two power circuits for dual fans. I only used one of them, the ORANGE wire, and oddly enough, on my controller, it had an inline fuse installed, and the blue one didn't. I think they meant to put it in the RED positive (+) lead to the battery, but I just went ahead and installed an extra one in line to the hot wire on the battery to protect the entire circuit. You can't skip that step!



This should look familiar. You are going to unbolt the relay box and the other two relays, and flip them upside down for a minute to gain access to the two signal wires to tap into. The pic was taken after mine was completed. Note an extra conduit going under the front end of the relay box.







-R

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1994 D21 2.4, 2wd, 5spd XE

TheRepairMan

! Just a strong word of caution before we continue. All of the cooling system electrical connections are critical to the proper operation of the electric adjustable cooling fan! Taking short cuts as well as not properly testing the integrity of the entire installation could lead to a catastrophic engine failure!

If you have any doubt's about completing this installation properly, then DON'T attempt it! Period!

Okay, so if you are going ahead, by now you've got the fan installed, and you know which direction the wires are going to run, so the logical thing to do next is mount the fan controller half way in between.

I removed the coolant reservoir to give me a little working room. This corner directly behind the right headlight was the best location for the controller I used. The plan was to keep it accessible but mount it solidly to the inner fender, and this worked out very well. The wire lengths were almost perfect and the controller was pretty well protected from a direct hit from the elements.

There was plenty of room to get a drill in there and drill a couple of small holes to mount the unit with two sheet metal screws. I made a template of the bolt pattern from the controller to a piece of paper, and then marked where I wanted the holes in the inner fender with a sharpie.

Note the light blue square with the white dot in the center located on the upper right hand corner of the controller ...that's the adjustment switch, or rheostat, to let you set the temperature at which the fan will come on.

It will require you to use a very small flat head screwdriver to adjust, (a Craftsman pocket screw driver was perfect), and there is enough room to get to it even with the coolant tank back in its place, and the engine running at full operating temperature. No problem. Later, during the first warm up test, I just watched my truck's temperature gauge to set it where I wanted, and then fine tuned after the fan cycled a couple of times.

Also, note the ORANGE wire coming out of the upper left hand corner of the unit that has an ATC fuse holder in it. That's where I decided to use a 25 Amp circuit breaker going to the fan instead of a fuse. That's what the fan manufacturer recommends doing as they state the fan "can" draw upwards of 16 Amps or so upon start up ...but it falls back to around 7 Amps at full speed. I found my new fan would actually pop a 20 Amp fuse at first upon starting, but after a little bit of run in time it is drawing less current. It hasn't tripped the 25 Amp breaker, so the circuit can handle it with no concern now. I'll illustrate the MAIN system fuse in just a bit.




The fan controller is mounted and I'm starting to make run the wires through their conduits and secure them in place. There's the fan power and ground wires in one and the controller's temperature probe in the other. The other couple of wires take off toward the relay center.



And here's the pics of the belly of that relay box. I found by testing that the small ORANGE wire running to the blue Check Lamp Relay in the center has Ignition power on it only when the key is in the run position, and that's exactly what the new cooling fan controller needed to work as designed... only when the engine is running.



Important note! If you are more comfortable stripping and soldering the last two connections than using quick connectors then it is advised to do so as the integrity of these connections are critical to prevent engine overheating or excessively high air conditioning refrigerant pressures. I can't over stress how important all the connections in this controller installation are!

I constantly watch the gauges closely during the operation of all my vehicles so I felt okay with doing the quick connectors. Done right they just don't fail any more often than any other connector on our vehicles. However, if you live in a salt air climate, or where salt is used on the roads during the Winter you need to go to extremes to complete the connections and insulate them from the elements.

So, here's that connection via Quick Splice Wire Tap - 18 to 22 ga. red for these smaller wires. The short section of YELLOW wire from the controller coming out of the conduit closest to you terminates in the Quick Tap and that Tap saddles over the ORANGE wire in the blue relay connector. Installed properly, it will not cut in half the wire to the relay, but just make a connection between the two wires. You can easily test your connection with an ohm meter or by checking for power on the end of the yellow with with the key on using your 12 volt meter or test light.

Remember that BLUE wire? It is the 2nd cooling fan power wire I mentioned earlier that won't be used due to the single fan installation here. We won't cut it off or disable it just because we may need it someday, but for now it does need to be tucked away in a safe manner inside the bottom of the relay box because it is hot when the fan is powered up.



So, that leaves us with the last connection to be made. The small (blurry) green wire coming from the controller has to go to, (if your truck has A/C), the Air Conditioning Compressor Clutch Relay.

On my truck it's the last single light blue relay mounted farthest from the battery, closest to the bulkhead, or firewall (as we use to call it). The A/C Relay has four wires coming up to the bottom. The one you need to tap into is RED with a BLACK tracer. It should be hot only when your A/C is turned on. That will insure that any time the air conditioning is running that the new cooling fan will be pulling air through the engine's radiator as well as the A/C condenser coil to keep the engine temperature and the A/C refrigerant pressures from going too high.

The GREEN wire from the controller was the only one that I found to be too short to reach the bottom of the A/C relay harness, so I had to extend its length by splicing in an additional six or seven inches of lead prior to the last connection. Since the bottom cap of the main relay box already has lots of holes in it I chose to run the addition of GREEN wire straight through one hole and on toward the bottom of A/C relay splice connection (not pictured).



And to complete these instructions, this is what I used for my battery connection (+) to the controller's red wire. The controller has a 40 Amp relay in it, but the fan manufacturer says to use a 25 Amp fuse to protect the whole new system.



I forgot to mention that you will have two BLACK ground wires to connect to the negative (-) side of the battery, one small Black wire from the controller, and a larger gauge that you have to add from the
negative side of the fan connector. Be sure and test your fan ahead of the installation for proper polarity and direction, and mark the fan's connector accordingly. Very important!



See, that was easy!

-

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1994 D21 2.4, 2wd, 5spd XE

TheRepairMan

Post up if you have any questions, or if something was unclear. I'll be glad to help walk you through this project as much as I can. I was careful in the project not to do anything that couldn't be undone if need be in the future. I'll be reporting back here with updates as needed.

FYI... I bought the 16" fan off a machine shop that sells on Ebay, and the fan controller at an Advance Auto Parts store, but there are many sources for these parts as they are common to street rod builders and car customizers. Be sure to follow closely the instructions that come with your kits as they may differ from the information I provided on the ones I used.

This mod is through the test stages on my truck. I have about 4 hours of run time on it in lots of different conditions, including rain, and so far it's working perfectly for me.

-R

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1994 D21 2.4, 2wd, 5spd XE

TheRepairMan

I forgot to show where the controller's temperature probe (bulb type) mounts. It needs to be placed in direct contact turned to run straight through the aluminum radiator fins as close to the upper radiator hose outlet as possible. Mine was just long enough and there is a gap at the upper right hand corner of the radiator between it and the shroud. The shroud, once bolted down, actually holds the new temperature probe gently in place.



Then, go over this electrical checklist from the controller.

(1) RED wire - fused, 25 Amp, to the Positive (+) terminal of the Battery.
(2) BLACK wire - to the Negative (-) terminal of the Battery.
(3) YELLOW wire - signal wire from ignition source, to the small gauge ORANGE wire of the blue
Check Lamp relay in main relay box, or any source that's hot with key turned to run only.
(4) ORANGE wire - to the (+) side of the cooling fan connector (switched power to fan).
25 Amp Breaker or a 25 Amp Fuse is also suggested here by the fan manufacturer to protect
the controller system in case the fan were to short circuit.
(5) BLUE wire - not used, but can power up a second fan if needed.
(6) GREEN wire - signal wire from A/C power source, to the red and black wire in the single, light
blue A/C relay's wiring harness, or hot only when the A/C compressor clutch is engaged.

And the very last circuit wire...
NOT from the controller, Fan ground wire (-) (BLACK or any color wire), but a single solid
ground wire added on from the Negative side of the Battery directly to the Negative terminal of
the new Electric Cooling Fan Motor.

Reinstall the cooling system reservoir and the air filter plumbing, and let the test run begin!

-Roger

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1994 D21 2.4, 2wd, 5spd XE

Grug

Wowsers! Impressive, very impressive. This write up should go to the top of the site along with the timing chain write-up. You should be working for Haynes or Chiltons.

Sooo...will we be seeing a similar write up (with pictures) when you do your timing chain?

Cheers!
Grug

TheRepairMan

Thanks, man! I wish I could take the time needed to do it right... get better organized with diagrams, and highlighted illustrations within the photos, plus it would help if the all posts here would remain editable for a longer period of time. I don't know if the mod is worthy of a sticky or not. That's not my call.

And, yes, when I get time to break everything down to do the timing chain. I'll document the whole process in great detail. I'll probably generate and edit the write-up within a software program specifically designed for technical writing, and then insert a lot of photos and illustrations where called for so I'll have lots of time to proof read and make corrections prior to posting it here. That's my plan, anyway.

So, here's my first real time road report on the truck's operation since the new electric fan mod...

My wife and I used the truck to go out to dinner, and to go get groceries last night. The first thing I notice is much less noise under the hood. That's because there's no mechanical fan spinning needlessly right from the start. The truck is noticeably MUCH quieter pulling out and accelerating, especially cold where the old fan clutch would still have been almost fully engaged.

Now, my wife likes to run the A/C ALL THE TIME. She thinks she can't breath unless it's on ...even when it is cool outside ...she just doesn't like the humidity, so naturally, when the truck's A/C is on now, by design so is the cooling fan, just like all modern vehicles. That meant, because it was pretty cool last night the engine temperature never even made it to half way where the fan would normally kick on. The ONLY drawback to all that is that it's not going to get better fuel mileage with both the A/C and the new Electric Fan running.

Those devices both consume electrical and mechanical energy in order to exchange heat to cooling, but even at that I'll have to say they worked very well, and the electric fan operating noise was completely undetectable when running unless we were at a stop, and even then I had to strain to hear it at all.

Most importantly, the alternator and battery were able to keep up with the extra voltage and current required, even with the headlights on. My volt meter never dropped below 13.3 charging volts at any time during my 6 hours of running so far. All's well at this point! Note, my battery and alternator are both about three years old with only about 15,000 miles on them so I didn't expect they wouldn't work well with this mod. I'm working on replacing as many interior and exterior incandescent light bulbs on the truck as possible with LEDs to make it consume even less electrical power. That makes for less load which equates to more fuel efficiency, and yes, even those small amounts count.

One other thing highly worth mentioning, if I haven't already ...with a total lack of mechanical fan noise, you can hear any, and all, engine internal noises. I'm hearing clearly, things there now I've never heard before, but that's a good thing actually, so I can stay abreast of any pending problems within the motor itself, and including all the belt driven accessories.

So far, I really like the fan mod overall, and the slight drawbacks are over weighed by the advantages. As long as it proves to be highly reliable, I won't be switching back any time soon.

-R

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1994 D21 2.4, 2wd, 5spd XE

TheRepairMan

Here are some links to the parts I used. I am in no way connected to or responsible for, the vending of these or any parts listed on this web site. I can't profit from the sale of these in any way. I simply found through my own research and testing that they were good values and that they works best for me and my application. Take a look if you are interested, and study all your options before making a decision for yourself.


I was unable to find a fan this size at this good of a price anywhere else. This seller has a real brick and mortar automotive machine shop and has been in operation in Kingsport, TN for over 15 years. Skip White Performace-Home of Racing Performance

The 16", 12 volt, reversible, push/pull cooling fan...

Super 16" Reversible Electric Fan 200 Watt HC 7105 | eBay




The Adjustable Electric Fan Controllers are available through just about any automotive parts supplier. Just make sure you get one with the temperature probe that slips in between the radiator fins instead of one that has to screw into the water jacket or threaded port somewhere on the engine.

The Adjustable Cooling Fan Controller with Relay...

Buy Imperial Adjustable Thermostatic Fan Control 226204 at Advance Auto Parts



All other hardware, electrical connectors, conduit, nuts and bolts, etc., were easily obtainable at my local hardware and automotive stores. I guess I had another $15 to $20 in that stuff, so a total right at $100 for the whole project.

-R

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1994 D21 2.4, 2wd, 5spd XE

Erics_Daily

Why is this?

TheRepairMan

Whether to use a temperature probe (bulb) type, or one that you have to thread in somewhere? Well, it's your choice, but just from my own experience the probe is much faster, easier, and works very well. Why would you want to mess with extra plumbing if you don't have to? Trying to find or make a hole, thread it to some odd size, chase down adapters, and then hope nothing goes wrong with your new kit, or the plumbing. Not me, if there's a choice ...plus, I prefer to be able to reverse or uninstall any kind of mod I do.

I guess you could say I'm more of an electrician than a plumber.

-R

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1994 D21 2.4, 2wd, 5spd XE

SPEEDO

^ I am with you, I like to un-do things if I have to....

TheRepairMan

Short term update: It's been a couple of weeks, and this was the coldest day I have run it so far. One of those mornings you really need some heat and defrost, and I'll have to say it all performed just as planned. I couldn't be happier... well I could ...if it would get about 50mpg, but I think we all know that ain't going to happen. It did seem to warm up quicker, and my drive to work this morning was plenty warm inside the truck, 27* outside, and the cooling fan never had to run even once, and that was even sitting through a few red lights.

Coming back home the long way including stops, ambient temps were around 50* and the fan cycled two times during 1-1/2 hour drive in traffic. The new fan cools it quickly, and only ran for about 1 minute each time. Battery voltage never changed, although we know it consumes a few amps, the charging system was easily able to keep up.

The truck warms up slightly faster, has slightly less load on the engine almost always, and cools down faster and better than it did with the mechanical fan and clutch.

Though testing has been short, this appears to be a very good mod, so maybe we do need to request it be made a "sticky" here.

-Roger

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1994 D21 2.4, 2wd, 5spd XE

SPEEDO

Thanks for the up-date, how hot are your summer temps? My area gets to 110-115+ (it hit 123 one summer) think that set-up could keep up?

TheRepairMan

Yeah, it's only passed the mild weather tests so far.

It doesn't get nearly that hot here where I live. It might top out 95* to 100* once in a while, but I can see no reason this system should not be able to keep up and cool the engine very well in average climates. That said, under the most harsh of conditions, it will work the alternator and battery just a little bit harder. That means they might run hotter than normal, so in those extreme high temps, if your mechanical fan is keeping it all cool then you may be better off keeping it in operation.

I don't know if going with an aftermarket electric cooling system like this is more reliable than mechanical in the long run or not. It has to be a little more efficient in average weather. I am thinking about running a second, but smaller, pusher fan in front of the radiator and condenser just as back-up cooling, but not sure about that yet. There's not much room up there and it would have to be on its own dedicated circuit to be a redundant system to protect the engine. Just thinking... 8"... 10"... I'm not sure.

Either way, I'm sure going to put it all to the test next year, with high hopes that it gives me no problems. This forum will be the first place I let know if any of it fails. I don't have any reason to believe it will from what I've seen so far. Eventually, everything electrical and mechanical fails, but the unknown is how long any system will last.

-R

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1994 D21 2.4, 2wd, 5spd XE