Hey guys, wiring question here:
My original 1993 FD radiator fans gave out, and I am going to be replacing them with stock fans from either a 99 spec rx7 or an rx8 (yes, the rx8 fans are interchangeable with the shroud from the 1993 radiator shroud). The question is that the 99 spec have two wires from each fan vs 1993 FD fans have 4 for each fan. So how would I wire these up to the stock engine wire harness?

 

Fans from newer Rx7s also have four wires from each motor.












The 99+ fans have a different style connector and have to be re-pinned or switch to another type of connector.

 

To answer your original question, you can wire the fan in a variety of ways to work in a four wire car, however you'll lose the "Low speed" functionality of the fan. You may also have issues with relay loading as four wire setups are typically 2x20A and a two wire will be 1x40A (or scaled as needed for the car)

In short, it's better to stick with four wire fans if you can. Follow andre's advice on choosing the right fan for your car.

 

Thanks! I actually picked up the rx8 fans today and yes you were right they are also 4 wires. So now im gonna go ahead and wire them up to the stock 1993 wire harness. I dont know if you have done this or not and might have the color to color combo. Otherwise im gonna crack open the wiring diagram for the cooling fans and figure it out.

 

http://www.fd3s.net/fan_circuit.html

This is the site I use to look up the fan circuit colors real quick. Some of the 99 fan colors were different and also pinned into the connector in different positions than the stock wires. So what I did was use a battery and leads, to power the fans up and figure out which wires and polarities made the fans spin the correct direction. Then after I had "labelled" the fan wires, I replaced the connectors and pins on both the fans and engine bay harness. I used the 4 pin connectors from this site:

http://www.cycleterminal.com/250-housing-lance.html

 

Yeap thats the same way i figured out their polarities. I still have my stock fans hooked up, and I labeled them prior as well. So just gonna play a little hook up tomorrow tell you how it turns out. The rx8 fans are much cheaper then anything else out there, and they should work just as well as the 99 spec.

 

And also, thank you so much for the connector link, I just ordered some plus also my relay pin connectors were messed up pretty bad got them as well!

 

I just picked up a RX-8 2009+ fan assembly which has 4 wires on each motor just like FD fans. To get them to spin the correct way to "pull" air I had to use black and yellow to ground and green and blue for postive. Thought that might help someone here.

For my race car which uses no stock relays, I'll be powering green for low speed, and green AND blue for high speed on each motor.

 

they pull in rx8s. so you it is wired normally.

 

anyone know the cfm of the 09+ rx8 fans or the 99+ rx7 fans over the 93-95

 

same^, are these better fans than FD?

 

There is no measurement data like that out there. The new car features for the rx8 and also I'm assuming for the newer rx7 talk about increasing the efficiency and decreasing noise with the new blade design. Plus the black blades look nicer :-D

 

I've ordered a set for the 20b RX7 with a FMIC setup. RX7 fans will be replaced with RX8 fans, inside the RX7 shroud with back-to-back comparison tests showing ambient vs coolant temp

The entire factory fan wiring harness will be removed, 2 relays will be installed, one for each fan. Connectors will be cut off and wires will be spliced into the relays. Relays will be triggered by EWP Craig Davis Fan Controller ground switch.

 

Thought your car already ran cool like right around thermostat temp or whatever target temp you have in the EWP controller.

Some data is better than no data. Interested to see the results. Take a video of how the stock fans sound on full blast vs the rx8 on full blast. Wonder if they sound different.

 

When temperatures are in the 70's and low 80's the car will maintain around 180-190F water temps on cruise and no higher than 195-200F in long periods of idling/traffic

Now that the weather is hot hot hot, sunny Alabama, humid 100+F, road temps sometimes exceed 140F as seen with infrared thermo. Consequentially, coolant temps now average around 210-215 with a max of 220F in traffic/hill-climbs and a stable 200-205F on the interstate.

The EWP is setup to run full blast @ 160F, but the heat is overcoming the system at this point.

One fan that makes an extremely audible squealing noise on initial activation for around 20 seconds. This fan also stops faster than the other with switched off. Time for replacements, so going to give these rx8 fans a try!

 

^^Interested to know the results. Keep us posted!

 

Per this thread:

https://www.rx7club.com/3rd-generati...grams-1085386/