I have been planning to convert all our truck electric fans. I was hoping to build a standard wiring harness to work with all of them using common parts. I do not want to use a store bought fan controller because of their reputation for giving out. I believe I have found, what I consider, the best option for what I am trying to do. However, I cannot find a design that eliminates the probe that sticks in the radiator. I do not want to go that route. However, any switches I find either tie into the ECM or require some kind of special hardware or parts that are model specific. Any thoughts or suggestions of this?

 

It'll be hard to do without a probe in the radiator. Are they all rangers? If so then you can do a probe setup in a t connector near the t-stat housing and just build however many you need and it will work on all the trucks. Also after having tried a couple different controllers i settled on a Delta current controller. It has been on for going on 3 years now and no issues. Its designed for race applications so it can handle high under hood temps with no issues but it does use a radiator probe but i believe they can send you just a threaded probe to use in the coolant line. To my knowledge none of the stock rangers have the ECM control capabilities. Also Ron Davis makes quality race level controllers.

 

Do you happen to know where I can see of a photograph of the set up you mentioned? One is an 87 Ranger and another is a 96 F250. I have other vehicles I plan to do this to but those are the most pressing.

 

First you have the e-fan(s) and it's high amp relay(s), this is a separate system, and needs to be wired with larger gauge wire for the 30-40amp draw, also with correct fuse for the amperage.

Now you need something to activate the relay(s), since this is a cooling fan a temp sensor would be best, this is the low amp side, and it is often best to use an adjustable sensor as each vehicle and climate requires it's own best on/off setting.
Since the fan cools the radiator it is best to check the temp on the coolant in the rad.
The "off the shelf" sensors that insert into the rad fins are fine, but if you don't like them then a sensor that inserts into the upper or lower rad hose will work as well.

BMW, Saab and VW used these, it is a metal housing with a bung to screw in the temp sensor, you cut your existing rad hose and add it in between with 2 hose clamps.

The sensors can be 1 speed or 2 speed, these are just to activate the high amp relays, so are low amp only.

This page has info on in hose sensors and also general wiring for e-fans: http://www.therangerstation.com/tech...tric_fan.shtml

For lower rad hose you want activation at about 195degF
For upper rad hose 210degF
Radiators have 15degF cooling without fan activated, and coolant flows from top to bottom.
Engine will be running normally at about 200degF at upper rad hose, t-stat should be 192/195degF, so lower rad hose should be 185degF at that time, 200 - 15deg = 185

 

Great read RonD. never even saw that one when i did my install definitely a clean approach with a good parts aftermarket in case things go out. May look into this for my next project.

 

I wish I could locate a Volvo.

 

Consider the Ron Francis controller. If you use a two speed fan, be sure to know the "start up" amp's for the second speed. many controllers come with two 30 amp relays, but some of the more common two speed fan swaps (Mark VIII or Taurus) require that the second relay for the second speed be a 40 amp.

I've used a couple of different controllers, and have settled with the Ron Francis unit. His temp sensor IS NOT a probe you stick into the radiator; this can seperate the fins from the core tubing, rendering an area of your radiator useless. Instead, they have an eyelet type temp probe that you place under one of the intake bolts, much more efficient.

They also have a great customer service group.

 

Thanks, I had not heard of them before. I will check them out.

 

I had also bought a controller that came highly recommended from the early Ford Mustang folks, "DC Controller". He's good as well, but is very, very slow in filling orders. This is why I went with Ron Francis for my truck. Also a great controller, and their customer service is tops. It comes with good quality guage wiring, it's labled on the wiring itself as to what it connects to, and the looms are good quality. Even though the connectors are also better quality than most of the stuff we can buy at the auto parts store, I ditched them and soldered/heat shrinked all my electrical connections for saftey and low resistance.

 

I will look them up as well. I checked out the other one you suggested and it looks like better quality than others I have seen. For the pricing I would hope so at least.

 

True, but in this case, "you get what you pay for". The Ron Francis controller comes with the circuit board with two relays, two built in breakers, screw connectors for the wiring to attach onto, dip switch settings to control the temp that the low speed fan comes on with (5 degree increments with LED colors to let you know the temp settings), and an option switch to allow or disallow the e-fan to run a few minutes after the vehicle is turned off. Plus ALL wiring that is color coded and labeled as to its connection and use. And, a temp sensor thats within an eyelet installed under a bolt; no silly probe that you ruin your radiator with. It's a kit designed around hot rodders, so it's clean, easy to install, and top notch. Well worth the price. Check Ebay; I ended up buying it from Summit, as I had a coupon code for a discounted price.

Sure, you can buy cheaper, but tha's what you'll get, cheap. And since I drive my truck almost daily, and tow a camper periodically, I don't want to risk a cheap controller or makeshift setup failing on me while in traffic and cooking my engine before I have time to react.

A true turn key type application. You'll want to keep this controller for any future vehicles if you trade it in! I kept the stock Rangers noisy clutch fan; if this truck leaves my ownership, the clutch fan goes back in, and the controller and e-fan stays with me! It's already been on one other truck that I've owned prior to this current Ranger.

 

I agree with you. I am a believer in buying quality. I would rather spend the money once than over the life of the product. The only real issue I have is I wanted to build this myself. I just want the knowledge.

 

This you can easily do then. You'd need two relays (one for low speed fan, the other for the secondary (high speed). The trigger for the low speed relay would be the A/C clutch (you want the low speed fan running to draw air through the A/C condensor and radiator anytime the A/C is running), and the trigger for the high speed would be the temp sensor (I'd strongly suggest using the type that attach under an intake bolt eyelet over thos probes that you poke into the radiator fins). Each relay would have it's own battery feed, and have it's own fuse. Then a ground to each relay, with the relay output unning to the respective wire of the e-fan; a two speed e-fan would have three wires, a ground, its low speed, and its high speed lead. This would not however give you any adjustment to what tempurature you want the high speed to turn on; it would be at the setting of the temp sensor itself, as it is the trigger for the relay. The controllers you can buy today have a potomiter (or in the case of the Ron Francis controller), dip switches to initiate thetemp sensor trigger to turn on the secondary speed. You can design a circuit for this, but I don't have that one.

I'd use a 30 amp relay for the low speed, and a 40 amp relay for the high speed, as most 2 speed fans have an initial current draw of about 32 amp start up for the high speed , then taper down to below that when running.

And consider upgrading your alternator from a 95 amp to a 130 if you have not done so already, as e-fans can put a slightly higher demand on your charging system.

 

I have all those parts and the proper wire size. I have a couple of different design layouts that i am looking at. The only thing I was missing is the temp switch. But now i have some ideas on how to make that happen.

 

It may or may not help you but my DC unit had quite a large range of adjustability. I ended up cutting a wire to the probe by accident (chafed against the shroud) and ended up slicing in a probe from from a cheap store bought kit for cost reasons and it work just fine i was able to adjust the on off temps to make it work perfect with the kit. If you could find a simple probe with a two wire lead which is what most of the controllers use for their sensors you should be able to splice it in and adjust it to work and the temps you want. Ive seen kits with a T connector and thread in probe that you can use in the upper radiator hose. Sounds like that may be a perfect fit for what your looking for.

 

Do you happen to have any photographs?

 

This one doesn't show the probe but you can get them separate or buy kits that have them included. Just need to verify the radiator hose diameter as these adapters come in pretty much every size. And also if no probe included you'll need to very thread size so you get one that fits.

 

That is what I am thinking. I have a metal tube that can replace my upper rad hose.

 

I wouldn't use a solid material to replace the whole tube the motor does a fair bit of moving and those plastic tanks on your radiator won't fair well with a bunch of side to side motion with a solid hose.

 

I have made them before with rubber ends on them. I did not meant it would be solid metal on metal.

 

You should add a high water float sensor cut-off as well, lol.

I always thought that would be cool, e-fan shuts off automatically in high water crossings

 

Not a bad idea.

 

Even easier, stay out of high water!

 

Now where is the fun in that?

 

It can be lots of fun...but more than just an e-fan shut off mod would be needed...I'd be more worried about water getting into the air cleaner box, so that would be one of my firsts on a list of things to make my 4x4 Ranger "deep water ready".