Electric Cooling fans and wiring.
 

So as with most gear heads HP is what is almost always wanted. So is longevity. So being that I was one to never mess with what works this is something I always thought of but never did. So I looked it up of course. Adding a electric fan and getting rid of the clutch style. SO by looking it up I noticed that info is all over the place. My question is. Is there just one thread or post or sticky note that has a list of things needed and how-to's? Other forums I had been in someone took all the info wrote a complete or semi complete article on what is needed and what works best. Basically meaning. I can take a copy of a list of parts needed to the junk yard and say hey this works and get it. I have noticed a few have used Intrepid cooling fans and wired them up to toggle switchs or probes into the radiator while others have done the A/C 12v wire with relays and temp switchs on the side of heads.. Well what about that person who is not wire harness making savy. Do they make or has someone made a harness. Has anyone used more of one brand of temp switch over others. Like I said. I did use the search and like I said also info is spread out over a vast number of threads. So yea back to the question at hand. Is there just one tech article that has all the info needed to just have someone who wants to venture out to the electical fan install world and have one direction on what to use and how to install. Also I do know that the fans themselves are not like a direct fit and brackets or ways to mount them will have to be done by said person IE: brackets or any means of mounting. Thank you

Following, I have a fan in storage waitting for an install...

I don't think there is a "one size fits all" write up for the electric fan(s) installation. Some people run a/c, some don't, etc.. It's really going to make a difference as to what engine you're using also and how much room you have between the engine and the radiator There are always lots of variables to consider. Are you dealing with a stock V6? Do you have any idea how to do wiring to make it safe and last? Just trying to get a feel for what you can and can't do here. The Intrepid fans fit the stock radiator like a glove. You'll have to make some basic retainers to hold it snug against the radiator once you've trimmed it to fit snug between the tanks. They are almost perfect in this regard. Wiring is pretty simple from what I've seen. I don't say that lightly either, I'm pretty inept but got it figures out. I have a schematic that I put together that will work with switches in the heads like you mentioned or can be wired for use with the 0411 computer but it would require having the computer program modified for that to work. Or you could just do the rocker/toggle switch thing but that means you have to always monitor the temps yourself and that's a big pain in the butt to keep it from an over heating situation.
I think there are about a zillion ways it can be done, some better than others.

Well mine is all stock. So the junkyards are finally opening around me. I am off work so I can go get what I need. IE: year of vehicle. and If you could send me the wireing diagram and which switch to use and location of said switch that would be awesome.

Post number 373 in my build thread has my write up from when I did mine with an intrepid fan.

ok do you have a wire diagram. and also what about using heat temp switch that i had seen in other write ups. i dont want to shove probes in anywhere. and of course i dont have access to a computer to turn on the part through the ecm

I'll give my $0.02

I use a Dodge Intrepid fan. I've seen two different types of these fans, one with more rounded edges and one that's more flat and squared off around the sides. I used the rounded one. I don't have many pictures of the fan before I started messing with it, but I do have this picture of a sticker that is on it.

https://i113.photobucket.com/albums/...507_191205.jpg



I cut off the original mounting tabs on the sides of the fan, 2 on each side. After that, the fan will almost drop right onto the radiator and covers the entire core. No way to mount it at this point, but I had something that fit.

https://i113.photobucket.com/albums/...507_190832.jpg

https://i113.photobucket.com/albums/...507_191157.jpg

https://i113.photobucket.com/albums/...507_191229.jpg

https://i113.photobucket.com/albums/...507_190922.jpg



I wish that I had some pictures of my mounting solution, but I think I was just trying to get everything back together at the time, so I didn't take many...

For the bottom, I took some flat stock aluminum bars, bent 90 degree angles in them, and bolted them to the bottom of the fan with the bent out part facing downward. These line up and drop into slots that the original fan shroud dropped down into, so that supports and locates the bottom of the fan.

For the top, I created 2 more straps in the same manor, but I actually bolted these directly to the top of the radiator through some small holes made in the very top lip of the radiator core. You can see them in this photo.

https://i113.photobucket.com/albums/...512_200129.jpg




To keep the radiator in place, I ended up modifying the original upper part of the fan shroud (since that's what keeps the top of the radiator in place in stock configuration) and reusing it. I left enough material to where it almost looks untouched at first glace. Doing this also let the AC lines rest on it just as they did originally, so I don't have to worry about them getting chafed.

https://i113.photobucket.com/albums/...512_200205.jpg

https://i113.photobucket.com/albums/...512_200633.jpg

https://i113.photobucket.com/albums/...512_200641.jpg




As far as wiring, I originally had them wired up to come on with the AC via the compressor clutch power and with a temp probe in the passenger side head. The Intrepid fans are 2 speed, and I had these two "triggers" wired to relays that controlled the two speeds, so they were completely independent of each other, which was intended as a fail-safe.

https://i113.photobucket.com/albums/...510_173052.jpg



That ended up not working as I had planned though... I had some AC issues and the freon leaked out, so that trigger stopped working because the AC wouldn't engage the compressor clutch. Then for whatever reason the first temp switch I installed in the passenger side head failed, I replaced it, and the new one worked for about a month and gave out too. After almost overheating a few times I threw all that wiring out and wired it directly to an ignition on source to trigger the relays, both speeds, and that's how I ran it through the rest of that summer.

Once I got around the rewiring it, I installed a 3 position switch in the roof console (along with some other switches for lights and winch arm), so now I have full control of the fans. It's still fed through ignition power so the fans will only run when the ignition is on, but I can either have them run on low speed (which is normally where I leave it, as even the low speed is adequate enough to keep the 4.3 cool with the AC on in the Florida summer) or I can run both speeds and kick it into high speed, which I use every once in a while if I'm pulling my trailer or if I run into a store and the wife decides she wants to stay in the truck with the AC running or something. I can also completely shut the fans off with the switch, which I use if I'm on the highway and there's plenty of airflow to not need the fans on. It's maybe an overkill setup, but I like the control I have over them.

https://i113.photobucket.com/albums/...511_213926.jpg

And some thoughts .

With A/C you may want to run a single fan.
The fans may be switched through relais with separate wiring and adequate fuses.
The fans may be cascaded for the temperatures they activate i.e. the first one runs with A/C on and also runs with coolant temp above xxx degrees F, while the second fan kicks in at xx degrees more than the first one. Thermo switches are available for this.

Still thinking about that issue with my build. Probably going for a three fan setup, having two small ones at the bottom and one big one above and between them in the middle of the radiator.

Some manufacturers and aftermarket shops have kits for including the temperature switches, relais, fuses and pigtails for the harness.

Another more technical option is to let the factory computer control the fans. It's not enabled from the factory, nor is the computer plug pinned for it, but the 411 computer can be altered with tuning software to enable the fan trigger at a predetermined temperature based off the existing temperature sensor and/or with AC activation. Then you just need to pin the plug and run that wire to trigger your fan relay. But I think it's limited to a single output (a single speed), however I could be wrong about that.

There are about a million fan controllers available from Summit Racing, etc. that come with wiring harnesses and diagrams. That's probably the way to go if wiring isn't really your thing.

I got mine from Delta Current Controls, but I'm not sure if he's still around. I'm running intrepid fans, too.

The one that I've never had too good of luck with is the type that use the probe that sticks into the radiator fins to read temperature.

The first time I used one was on an 82 Monte Carlo that I swapped a 350 into and put a set of Spal fans in it. Had a thick aftermarket aluminum radiator. It could very well have been where I placed the probe that gave me issues. I put it in the fins up high near the top of the radiator near the fill cap on it. Thinking back, that's not a good location, because if the coolant got low the sensor wouldn't read the correct temp, which would explain why the car would almost overheat sometimes before the fans would ever kick on, in the winter time none the less.

The second time I used one was in a 91 Toyota Pickup that I tore apart and rebuilt, it actually controlled the fans fine, but it control module the sensor was connected to, 2 of them burnt up within a couple months... I eventually hardwired that one in a similar way that the one is now wired in by Blazer.

I followed blazen’s steps for mounting and which fan to use then I got a controller with a probe that goes into the block. Used a separate relay off the controller for the fans (didn’t trust controller relay quality) I have a master power switch for the controller incase I need to kill the power (water or giant mud pit) and I have no complaints about it plus I was tired of going through clutch fans