Taurus Fan Wiring Problem

Bullitt · Sep 27, 2009

I've had a Taurus fan in my car for a while now, but just had the low-speed hooked up to a manual switch.

In my quest to make this automatic, and add in a manual override for high-speed (also will tie in the A/C to this), I did some searching and came across a wiring diagram that I modified slightly for myself...

I thought I made the changes correctly, but I guess I didn't because it won't work!

Any help would be appreciated!!! The diagram is attached... Thanks!

pyroman · Sep 27, 2009

Ok let me make sure I understand you first. Right now the only way the fan comes on is by a manual switch? And what you want to do now is to make the low speed setting come on automatically but you want to be able to switch it to the high speed manually which will shut off the automatic low speed setting?

Tim65GT · Sep 27, 2009

Things I've found out from research and personally wiring my Taurus fan:

1. The Taurus fan cannot have power applied to the high winding and the low winding at the same time.

2. The high speed will melt a typical 30/40 amp Bosch type relay. A heavy duty relay is required:

View attachment 244279

The heavy duty relay does not have a normally closed 87a terminal, so removal of power from the low speed relay when the manual high speed switch is turned on needs to be accomplished by a separate means. Since you already have a third relay, the 87a contact on it would be used. It looks like that was what the original wiring may have been doing.

I re-worked the drawing (green lines) so that ground is now applied to pin 30 and 85 of the control relay. With the high speed switch off, the relay is at rest with ground going from pin 30 to pin 87a. This provides the ground path to the low speed relay coil. When the temp switch reaches its preset, it will send ignition power to the other side of the low speed relay coil energizing it and sending battery power to run the fan.

When the high speed manual switch is engaged, 12v will be applied to the coil of the control relay. Ground will then be removed from pin 87a and be applied to pin 87. This will remove the ground from the low speed relay and apply it to the high speed relay. It has battery power on pin 30 and pin 85. This will energize the high speed relay and apply battery power to the high speed winding of the fan. Ignition power (the old yellow lines) does not have to be routed to the high speed relay.

Bullitt · Sep 27, 2009

Thanks Tim65Gt!

That's exactly how I want it to function.

Sadly I put it all in without benchtesting. Learned my lesson!

I'll give it a shot and let you know how it works.

afast93stang · Sep 27, 2009

Save the headache and get a Delta Current Control module. It automatically/gradually powers up and down accoring to engine temp. Its well worth it....

stonecoldtx · Sep 27, 2009

afast93stang said:
Save the headache and get a Delta Current Control module. It automatically/gradually powers up and down accoring to engine temp. Its well worth it....

I agree about a fan controller, but I personally used a SPAL, and it works flawlessly with dual GM LS1 F-body fans on a Fox-body crossflow radiator in my '70 Mustang.

I am using a GM temperature switch (supplied by SPAL) that signals the controller to turn on the first fan at a certain temp, the second fan at a different temp and when I turn on the A/C, both fans come on at once.

They also shut off based on engine temp . . . it's a pretty cool setup, pardon the pun

BarnStang · Sep 27, 2009

Fan Control

Here is the link to Delta. Used this product a long time ago and worked great then. I'm sure it' even more improved now. We have installed two of the Spal controllers-great set up too. THese are both geat solutions but can be a few bucks to impliment. You can run the relay setup cheaper.

THe DCC setup we used on a 68 Coupe with an older EFI motor out of an NMRA Renegade class car. It had a pusher Spal fan in it that was so loud at high speed you couldn't here yourself talk standing in front of it. The DCC controler functioned exactly as described above-it took the fan speed down and ramped it up as a function of engine temp. Never got over half speed idle. Huge difference in noise reduction.

pyroman · Sep 27, 2009

I'm using the Hayden fan controller. For those who haven't seen it, there is a good writeup on it here:

FORDMUSCLE webmagazine: Junkyard Electric Fan

BarnStang · Sep 27, 2009

THat looks really cool. Very cost effective. I bookmarked that article. THere test of the system was pretty extream. Very affordalbe solution.

Bullitt · Sep 27, 2009

afast93stang said:
Save the headache and get a Delta Current Control module. It automatically/gradually powers up and down accoring to engine temp. Its well worth it....

I ordered one of those units quite some time back. I waited almost 2 months with no word from the MFR on the delay (they did not reply to e-mails either). Finally issued a dispute through Paypal and got my money back, but I was not pleased!

Needless to say, yes I would have liked to have one of those, but the whole experience did not endear me to the company.

Bullitt · Oct 2, 2009

Tim65GT, just wanted to let you know your modification worked perfectly!!

Big thanks!:SNSign:

Tim65GT · Oct 2, 2009

Bullitt:
Tim65GT, just wanted to let you know your modification worked perfectly!!

Cool It's nice when you can do stuff yourself and when you hit a snag, having a place to get some help to get it going.

Since my original Aluminum radiator and Taurus fan install, I've gone from failed homemade controllers to adjustable Hayden Mechanical Tube type, Melted relays, Single high speed with HD Relay.

And now finally an Electronic Two Speed Adjustable Setup. It is consistant (The mech bulb sensor was not). The best part is that I built it myself and It's been through a few months of HOT weather, so I can say it works! Both Speeds are adjustable.

For those like me who enjoy building small electronic projects, here is how I did mine. Oh yeah, it was cheap. I used a sensor for a '95 Stang that goes in the waterneck -$4. The rest of the parts are pretty cheap at Radio Shack or your favorite electronics parts supplier. TIP31 transistors easily handle the relay coils. A LM339 Comparator or 324 Op Amp works. I used an old alarm module for the case.

Self Services · Oct 21, 2009

I would love to know about this. Are the fan speeds adjustable? Not sure how it's done.

Self Services · Oct 22, 2009

Tim65GT Iwould like to know more about your fan setup. I would like part numbers so I can build one for my taurus fans. Is the speed varible?

Self Services · Oct 22, 2009

Can I have more info on this? Are the parts at Radio Shack?

Tim65GT · Oct 23, 2009

I am traveling now, but when I get back next week, I can post the parts

hipwr1984 · Oct 27, 2009

Take off on the first schematic

I have put a taurus fan in my 84 and used a variation of the old school schematic put up by Bullit & Tim65GT. Thanks guys for the education and great visuals.

I had been running dual 12" fans but when the weather go above 90 and I put on the AC it started heating up so I did some research and the dual 12's pull 3200cfm together while the Taurus 2 speed pulls nearly 4500 on high. Anyway, I put it together with a HOT fused distribution block and a switched fused panel and four relays.

I added the fourth to override the high speed relay circuit and turn the fan on high whenever I run the AC. I completed the install this weekend and it worked great after a small correction to add a power circuit to the control relay. Yippee!!

The the low and high speed thermostatic switches provide ground. During low speed temperatures, the low speed relay gets its control voltage from the 87A post on the control relay. When the high speed thermostatic switch grounds out at 180, it activates the power through post 87 to the high speed relay and simultaneosly disconnects the power from the low speed relay post 87A so only one speed is running at a time.

The AC override relay introduces the ground to the control relay when AC is turned on and does the same thing as the high speed switch does. Now let's see if I can get ya a picture.

View attachment 60321

my email is csheran@verizon.net if you want to chat. Hope this helps. This site rocks!

Tim65GT · Oct 29, 2009

Self Services:

I would love to know about this. Are the fan speeds adjustable? Not sure how it's done.

I would like part numbers so I can build one for my taurus fans. Is the speed varible?

The fan speeds are fixed (High, Low or Off). They do not vary. They are controlled by the relays which energize by the temp sender and contol circuitry. One input to the two Operational Amplifiers (Comparators) is tied to the 5V regulator and the other inputs are variable by the 10K pots. This makes the low and high turn-on points adjustable. The transistors turn on to carry the higher current to the relay coils.

I posted the pics to show what I have built. I don’t know your capabilities with electronics, but if you want to attempt a project like this I just want to let you know up front, I think it would be about 4 out of 5 on a difficulty scale. You will need a lot of patience and unless you enjoy building small electronic projects, you would be better off spending the money and buying a fan controller of some type.

The sensor is from a '95 Mustang GT. I have it mounted in a '95 type water neck. Here are the part numbers and prices of the items I could look up.

Item Mftr Part number Cost Place (Pt#)

Temp Sensor BWD WT386 $3.62 O’Reilly
70A Relay Bosch 0 332 002 150 $13.20 eBay
30A Relays (2) Bosch type standard $10 eBay
Quad Op Amp LM324 $1.69 RadioShack (276-1711)
5V Regulator 7805 $1.59 RadioShack (276-1770)
Transistors (2) TIP31 $1.59 RadioShack (276-2017)
Variable Resistors (2) 10K - 15Turn $2.69 RadioShack (271-343)
Perf board $2.99 RadioShack (276-1394)

You will also need other various type project stuff like a case, wire, crimps, solder, heatshrink, fuses, and various ¼W resistors.

Self Services · Oct 31, 2009

Thanks for the info. I like projects that same money and doing it myself. I have to build 3 now. 1 for the jeep, 1 for the stang, 2 for the diesel truck. I am going all electric.

Self Services · Oct 31, 2009

Thanks

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