Thunderbird fan install on 2000 Ranger.

[68Electra]

I thought I would do a write up of my electric fan installation and share it with you guys.
Here is my 2000 Ford Ranger

Whats missing here?

I actually just forgot to take a before picture. Just imagine a mechanical fan with shroud.
Some of you may have heard of the 90-95 Taurus fan which puts out 4500 cfm on high. Well V8 thunderbirds in the 90s with the 4.6l had an even larger fan with that same motor. I got this at the Pick 'n' Pull for $25.

But you can see its huge. You would't think it would fit, but the ranger radiator is taller than it is wide. It actually extends down behind the bumper.

Now that motor is larger diameter and actually pretty shallow, but it is a tight fit in a compact pickup. You can see it hits the water pump pulley which is where the mechanical fan was mounted.

To trim it shroud nice and evenly, I used 3/4" masking tape to mask off the line to be cut.

I also used a 3/4" board so I could use a utility knife to make mulitple cuts until I cut through the plastic.

Worked pretty good.

I have a helper.

The factory mounting tabs go in my way, so out came the hacksaw.

Trimming mostly complete. Later I cut the tabs off.

Other side.

Oops, I didn't think to check fan clearance on the other side. Frankly I lucked out here. In fact I ended up spacing the fan back out 1/8th of an inch for extra radiator clearance from the blades.

The fan goes in sideways. I tried it both ways to see which gave me more clearance. The motor on the fan is larger diameter, but actually very flat, but there isn't much room. It is a compact truck after all, and the 4 cylinder is longer than a V6. Its hard to tell, but with the power connector up the motor is more offset away from the pulley.

I got some corner brackets, clip nuts and machine screws from the hardware store. I riveted the brackets to the shroud and used some existing holes and had to drill some others. I used three rivets on each because its plastic, but 2 screws on each bracket was plenty secure.

 

[68Electra]

To power it I really should have just spend the money on one of these LINK I just didn't want to wait for mail order. In the end because I broke my first temp probe, I spent MORE than if I had just bought the variable speed controller.

For anyone else doing this, unless you have larger gauge wiring and relays laying around, it would actually be cheaper to just get the flex-a-lite controller, which includes wiring. I bought this LINK kit but only ended up using the fan probe, and the relay because I broke the prong off one of my junkyard relays. The flex-a-lite has soft start, 5 second start delay, and variable speed.

The thing about the Taurus/Thunderbird 3 wire fan is you can't energize both the low and high speed inputs or you will fry the fan. It also pulls like 45 amps at startup on high. I put the probe near the outlet tank; my reasoning is that coolant entering the radiator is going to be hot, its only when airflow from the car moving isn't adequately cooling that I need the fan to come on. I also wanted the fan to run on low whenever the A/C compressor clutch was engaged so it would cool the condenser. Finally I wanted it to run on high when the A/C compressor was running and the coolant temp was greater than 185. It works great by the way. It was 105 on Monday and I was driving around slowly and stopping a lot at the junkyard, just left it running. I was getting in and out a lot, so I had the windows down and the A/C off. The fan would run for about 3 minutes at a time to keep the outlet temp below 185. Coming up with the wiring diagram was a bitch, I had to adapt what others had done, and the diodes were very important, because I had issues with back current keeping the relays engaged and also keeping the A/C clutch locked up.

I only found 30 amp relays, so I ran two in parallel, so you could just substitute a single 50 amp or better relay for the high speed fan. Theory of operation is that when the A/C clutch is engaged AND the temp probe is grounded (185 degrees or hotter) that the high speed relay(s) is energized and 12 volts goes to the high speed wire on the fan. The other relays get power through 87a of the high speed relay, so when the high speed relay is on it removes power from the other relays. Remember that if you power both the low and high wires it will burn out the windings on the fan motor. This fan moves a lot of air, so this was probably unnecessary. I was only able to get it to go to high by leaving the AC off and wait until the temp probe relay put the fan on low then turning on the A/C. Even on low it moves like 2500 CFM.

12 volts goes to the low speed relays, one for temp, one for A/C. The temp relay has 12 volts all the time so that when the temp probe is grounded (over 185 degrees) the fan gets 12 volts to the low speed wire. The fan will keep running after you shut off the truck until the temp probe gets below 170 degrees. The A/C relay runs the fan on low any time the A/C clutch is engaged.

The Diagram makes it clear as mud LINK

The two diodes by the motor keep the fan from acting like a generator when shut off or when going highway speeds and just bleed off back current to prevent relay damage. I don't know how necessary this part really is.

I can't emphasis enough though, I only kept messing with the DIY wiring because I had already spent bad money after good but couldn't return any of the stuff I had cut up and modified. Especially wrapping my brain around the electricity flow. I like to have never figured out that when the A/C clutch isn't engaged its + wire is grounded hence that diode. Basically once the temp probe had triggered, it would never unground and the fan ran forever. Plus with diodes you have to remember that electrons are negative and the real direction of electron movement. ARGH. I swear at the first sign of trouble I will just rip it all out and get the flex-a-lite controller.

Actual wiring part. I found a nice little spot for the relay box. My truck has zero options; 5-speed, roll up windows, non power locks and no carpet. I suppose if you have cruise control or ABS or something this space might be occupied.

I mounted a Radio Shack project box with a rubber isolator mount I scrounged off of something or other at the junkyard.

Here is my mad tight wiring. I used cloth tape to bundle the relays together and then zip tied them to the box. The box is not watertight, so I figured the more holes in the bottom, the better for drainage of water. The zip tie also holds a section of fuel line to support the other half of the box. No holes were drilled in the truck except for the radiator itself to mount the fan.

My dad raised me to be a big fan of soldering connections. I just wish you could buy connectors without the plastic insulators that you have to remove first. Then I used good quality shrink tubing. I even found some slightly wider connectors to connect to the maxi fuse instead of buying a fuse holder.

Yes, I am a dork. I have a label maker.

I have not however been able to verify an increase in MPG. My driving habits changed (job situation) so I don't have any A-B comparison.

Pictures of final product follow

 

[MMRanger]

Hi can I save your post on a spread sheet for personal use?

Thanks, I plan to install a fan myself. Oh, does this apply to the 2002 Ranger?

 

[Ronv]

Morning:

A real nice write-up along with pictures! great job .

The labeling might apprear superfluous but if someone other than you have to work on the fan for any reason everything is neatly laid out.

Ronv

 

[06RangerXLT]

i like it, but im trying to understand your setup. with the way you have it now, if you apply power from the ac being on, it will activate all your relays, because they are all connected.

maybe you can elaborate.