What now? Help please. Dual Fan Mix Up.

I had planned to do a Twin (Dual) Electric Fan Upgrade on my XJ. Parts ordered not Parts sent. I ordered a New Taurus 3.8 V6 Electric Radiator Fan and a New '97+ XJ 4.0 Electric Radiator Fan from one Online OEM Parts Store. I had ordered 2 Five Post 80 Amp Relays from a Different Online Store along with Wiring for a Single Taurus Fan Upgrade.

What was sent and arrived today were 2 Taurus 3.8 V6 Electric Radiator Fans; no XJ Electric Radiator Fan. From the other company, 2 Four Post 80 Amp Relays and all the wiring needed for a Single Taurus 3.8 V6 Electric Radiator Fan Install. I believe they will work, however, I need help on how they can be Utilized. I had planned to do a Setup that jeeperjohn had suggested in this Thread: http://www.naxja.org/forum/showthread.php?t=1002030&highlight=Taurus+Fan ,however, that is impossible now.

Even though a Dual (Twin) Taurus Fan Setup would be incredible Overkill and burn up a lot of Amps, I now plan to utilize the Low Speed Wiring on the Fan that would replace my Stock XJ Fan and setup the other Fan with the Four Post Relays. Would this work?

I have no Idea on how to fit the 2 Fans within the Radiator Mounting Area and how to Wire Up 4 Post Relays.

Please, help me out here and Post Up Constructive Thoughts about this New Setup. Any Photos of a Similar Setup would be helpful.

Thanks.

cher96 Vicki

cher96 said:

Posted by jeeperjohn

Click to expand...

I wish to use a Thermo Switch. How would it be wired up to this Setup?

I presume a Four Post Relay is only for a Single Throw Toggle (Off and On) and not for a Low On -- Off-- High On Toggle. Am I correct in this presumption?

Thanks.

cher96 Vicki

For a Four Post Relay, I found this.

http://www.lunghd.com/Tech_Articles/Electrical/RelayBasics.htm

A VERY basic circuit.

A basic relay circuit you can use for devices such as fog lights, electric compressors, c.b. radio linears, etc. When switch is in "OFF" position, no current flows to relay and device circuit is "OFF". When switch is in "ON" position, current flows to relay which switches "ON" high current to your device.

NOTE! THIS CIRCUIT SHOWS A DIRECT CONNECTION TO BATTERY FOR SWITCH! YOU SHOULD CONNECT YOUR SWITCH POWER TO A FUSE THAT IS CONTROLLED BY YOUR IGNITION SWITCH UNLESS YOUR CIRCUIT MUST BE ACTIVE WITH THE KEY OFF!

VERY Basic circuit.

Switch fuse should be 5 amps (or less) to protect against shorts in switch circuit. (Switch circuit can usually be ran from existing switched fuse in fuse panel.)

Device fuse should be same rating as relay capacity. (Usually 30 amps.)




Terminals found on a generic relay often used to control fog lights, horn, etc:

I had ordered two 5 Prong 80 Amp 12Vdc Relays because they did not have 5 Prong 30 Amp 12 Vdc Relays on their Website. I called them and complained because the ones they sent are 4 Prong. They are going to send two 5 Prong 30 Amp 12 Vdc Relays they have in Store Stock as reparation. They have since changed the Page to reflect that they are 4 Prong and not 5 Prong.

So, how do I make a 4 Prong 80 Amp 12Vdc Relay and a 5 Prong 30 Amp 12 Vdc Relay work in a Single Taurus Fan and a Stock '97 4.0 Electric Fan Setup?

Thanks

cher 96 Vicki

Before:

Detailed Description
Bosch Style Automotive Relay, 12 VDC 80 AMP SPST

Single Pole Single Throw
Normally Open Contacts
80 Amp 12 VDC Rated Contacts
Terminals:
0.250" for coil (2)
0.375" for contacts (3)

KEST KAR1280

Now: http://www.skycraftsurplus.com/index.asp?PageAction=VIEWPROD&ProdID=1503

Detailed Description
Bosch Style Automotive Relay, 12 VDC 80 AMP SPST

Single Pole Single Throw
Normally Open Contacts
80 Amp 12 VDC Rated Contacts
Terminals:
0.250" for coil (2)
0.375" for contacts (2)

KEST KAR1280

Is it impossible to make a 4 Prong 80 Amp 12Vdc Relay and a 5 Prong 30 Amp 12 Vdc Relay work together in a Single Taurus Fan and Stock '97 4.0 Electric Fan Dual Fan Setup with Toggle and Thermo Switch?

Anyone?

This is frustrating for me. I hate talking to myself... I never learn anything new by doing so.

Thanks.

cher 96 Vicki

Yes it is. You could have the Taurus fan on low speed along with the stock fan given a big enough relay. And a temp switch on the relay coil of the high speed Taurus fan setting using the 80A relay.

Think of a relay this way. Half of the relay, 85 and 86 is basically a gate using a low current draw coil. It takes power and ground. With both there, it pulls in an internal connector that passes high amperage out to the load whether it be a horn, lights, fan, whatever. The high amp side is on terminals 87 and 30.

So controlling when the primary side of the relay receives its power and ground decides how your new circuit works. You could run keyed power to 85 and run the ground on 86 through a temp sensor at a higher setting like 220. A switch could be used instead, or in addition to sensor-controlled high speed operation.

Fans are easy, you just have to keep in mind the number of amps they pull and size the wires accordingly. You must have fuses or fuse links on the power wires going into both sides of the relay.

Honestly though I don't think you'll even need the high speed setting on the Taurus fan. They move a ton of air.

Thanks. Now I fully understand the First Diagram by jeeperjohn.

Okay,

Taurus Fans High Speed Wire:

80 Amp Relay:
Toggle Switch to 85.
Stock Fan Hot Wire to Diode to 85.
86 to Ground.
30 H to High Speed Wire on Taurus Fan.
87 B to Fuse then Battery.

Correct?

Taurus Fan Low Speed Wire:

30 Amp Relay:
Temp Sensor to +
- to Ground.
One Prong goes to Low Speed Wire.
One Prong goes to Fuse to Battery.

Question: What keeps the two Relays from being Switched On at the same Time and trying to run the Taurus Fan at Low Speed and High Speed simultaneously?

Thanks.

cher96 Vicki

I reread the Thread on "Taurus fan wiring instructions."
http://www.naxja.org/forum/showthread.php?t=1002030

And, dummy me.... I reread this Post by jeeperjohn.

jeeperjohn said:

The ones in the diagram I drew are 5 prong. The low speed relay can be 4 prong but the high speed one needs to be 5 prong.

Click to expand...

I guess I am going to have to try and sell my extra New Taurus 3.8 V6 Electric Radiator Fan and extra 2 New Four Post 80 Amp Relays so I can buy a New '97+ Stock XJ 4.0 Electric Fan and a New 5 Prong 75 to 80 Amp Relay I should have been sent in the first place.

I really needed to get this done this Weekend because I need to use my XJ for my Kids to get ready for School in a Week or so here in Florida and get to the Store and my Doctor Appointments. What a Waist of Time and Frustration when Online Companies do not send what is Advertised or what was Ordered!

Mods, Please Delete this Thread... It is useless to say the least.

Thanks.

I'd wager just one Taurus fan is more than sufficient. Keep looking at the electrical stuff until it all becomes clear to you. This project could be done today with the parts you already have.

Good luck!

The only thing I can see with what I have is a Dual Simple Relay Circuit using a "Low On--Off--High On" Toggle Switch. That would leave out the Thermo Switch and the Stock Fan Controller. The Taurus Fan would be unable to stay on until the Radiator cools with this Design.

If you see it differently than I do, please Post Up.

Thanks,

cher96 Vicki

I found this and it looks like it will work with a Thermo Switch that can be set at 210 Degrees so the Engine will run at Optimum Temperature or there abouts.

If my assumption is wrong, please correct me.

Thanks,

cher96 Vicki

BB1980 said:

I came up with this one that uses only two relays and a three-way switch. I am only going to use the low for auto-on, and have the High wired for straight manual only for low speed wheeling or what not when the temps start to rise. The middle position on the switch would disable both for water crossings.

Click to expand...

that looks good to me

I may go with this Diagram. I am going to have to figure out which way is the best way to go.

This Site is not an XJ Site but it did have these JPGs.
http://www.geocities.com/smithmonte/Auto/MarkVIII_Fan.htm