puma

iTrader: (2)

I have a question about the wiring.

I know on the How-to, they say to get the wire from the relays in the engine bay, pass them in the firewall and run them to your switch. My question is, is there any way to take the connections inside the car on an other connector instead of running a wire through the firewall? I would like to keep my engine bay as clean as possible. Also, running wires through the firewall is a pain.

I checked in the electrical diagram book and it looks like it can be made. Anyone done this before?

Thanks a lot

puma

cewrx7r1

iTrader: (2)

The way you mentioned is for cars that have not had the recall for the cooling system and fuel lines. The recall placed a small black box onto the back of the ecu along with a small interfacing wiring harness. Later on the wiring harness change was incorporated within the main engine wiring harness.


From this black box is a wire and connector that is not used. It is this wire that you can GROUND OUT to turn on the fans as it goes to the fan relays. If activated for 2 minutes and the water temp is over about 180F before engine shutdown, the fans will run for 10 minutes for post shutdown cooling.

This has been discussed many times here and on the old RX-7 list. It is recorded on a few web sites.

puma

iTrader: (2)

i ain't sure i understand everything you said but the mod i am talking about is a switch you can activate so you can put the fan ON whenever you want, like when you are stuck in traffic.

i don't think i have the 10min after shut down recall because it never happenned to me that they stayed on after shutting off the engine.

thanks

puma

Brian_93

Puma,
I just did the fan mod a week ago, There are two ways to do it. You can wire it from the relay under the hood or from inside the ECU. This is how I did it a it worked. Its really simple.

Cooling Fan ModificationTesting the ECU/Fan circuitry1.

Uncover the ECU which is behind the "kick panel" in the passenger side foot well. You will need to pop off the door sill trim and then pop out all the fasteners holding the kick panel. It is best to go slow with this as the plastic can crack easily. Once the panel is removed, you can see the ECU mounted to the chassis.
2. Locate the single black wire (with female spade-type connector) coming out of the ECU that is not attached to anything.
3. Attach this wire to ground for two minutes while the car is running.
4. With the wire still grounded, turn the car off and the fans will stay on. 5. After 30 seconds, un-ground the wire and the fans switch to low speed.
6. The fans stay on for ten minutes.
Performing the "Fan Modification"
1. Disconnect negative battery cable.
2. Remove the scuff plate from the passenger door sill.
3. Pry off the kick panel on the passenger side (next to passenger's right foot) to expose ECU.
4. Unbolt the ECU. There are two hex bolts on the bottom and one on the top right. No need to unplug it.
5. Look for small plastic box (fan control module bolted on behind ECU).
6. In the 5-wire harness, follow the black/yellow wire until you reach a dangling female spade connector.
7. Run a wire from this connector to one pole of a switch, and run the other pole to ground. If you mount the switch on the center console, you can use the brass bolts there as ground points.
8. Connect the battery cable and turn on switch.

You should hear Relay 3 click on.Operation When you want your fans to come on manually, turn on the switch. In two minutes, your fans will be on medium speed. If the car was hot enough already (more than 221F - fans already at low speed) then your fans will switch to medium speed immediately. If you now want the fans to move up to high speed, turn on your A/C. If you want the fans to run after engine shutdown, turn on the switch 2 minutes prior to turning off the engine. The fans will stay on medium for 10 minutes. If you turn off the switch within that 10 minutes, the fans will run at low speed for the remainder of the time.Notes

About The "Fan Modification"
1. Only use it when it seems appropriate but there shouldn't be any ill-affect on the battery.
2. Don't ground the wire all the time as the fans will stay on. Be sure to allow for a cool down for the oil in the turbos.
3. The "cooling fan control module" is the small black plastic box mounted behind the ECU.
4. Sometimes the wire is behind the CPU and it is black with a greenish/yellow-stripe.
5. Yes, this mod WILL work in conjunction with a Turbo Timer!

You don't need to actually run the engine for the fan mod to work. If the accessory is on (ie. idiot lights lit) the fan will start running after 10 minutes. There is no harm in keeping the switch activated. The fans shut off and the only power draw is about 1 Watt from the relays. It shouldn't drain the battery unless the car sits for a long time. Don't forget to turn off the switch BEFORE the next time you start the car or the fans will start running even with the engine being cold.

This is really simple and striaght foward.
Good luck.

puma

iTrader: (2)

Ok then, here are some questions

There are two parts in you post, the one with the black wire and the other one with the black and yellow/greenish wire. Are we talking about the same wire? If not, why not using the black wire instead of the black and yellow? Why the black only for testing and not for the permanent mod?

Second question: What happens if you turn on the switch two minutes before shutting off, the fans stays at med speed and you turn off the switch before the 30 sec? And what happens if you don't turn it off, the speed will stay at med?

Third question: what happens if you turn on the switch before the fans started (because it wasn't hot enough). I suppose it won't do anything, the only thing that will happen is that when it will ask for low speed (when it gets hot enough), it will get medium instead. Am I right?

Fourth question : I suppose this means that the fan mod won't help in turning the fan ON before the 221 deg of the low fan speed? Is that it?

Fifth question: what do you have to do to turn the fans on at let say 200 deg?

Thanks a lot

puma

KevinK2

http://www.scuderiaciriani.com/rx7/fan_mod.html

This link covers most of this.

For some models (my 93), grounding the test wire will give instant med speed fans. for others, it's more conditional, like 2 minute wait for fans or already very hot coolant needed. In those cases, instant on demand fans can be had per the xxxvoodooxxx link at the above site, for an under the hood relay mod.

for the nice 10 minute timer run, gnd test wire 2 minutes before shut down, AND leave switch on xtra 20 sec before turning fan switch off. This will drop speed from med to low, and will not leave the relay on, which is a low amp drain.


ps, parking lites or cabin fans at 3 will result in cooling fans controleed at about 200F, for many.

pps, miata 207F fan switch:

If the timer ground provides instant on fans for your model, then the 207F miata thermal switch will work directly. If not, a 'voodoo' type mod can also be done to make the miata switch work.

puma

iTrader: (2)

the questions i asked are because i read the suderia site


"For some models (my 93), grounding the test wire will give instant med speed fans. for others, it's more conditional, like 2 minute wait for fans or already very hot coolant needed. In those cases, instant on demand fans can be had per the xxxvoodooxxx link at the above site, for an under the hood relay mod."

ok so i why are other talking about a different wire if you can use the test wire?


"for the nice 10 minute timer run, gnd test wire 2 minutes before shut down, AND leave switch on xtra 20 sec before turning fan switch off. This will drop speed from med to low, and will not leave the relay on, which is a low amp drain."

ok but what if you close the switch before the 20 sec, will the fans turn off?



"If the timer ground provides instant on fans for your model, then the 207F miata thermal switch will work directly. If not, a 'voodoo' type mod can also be done to make the miata switch work. "

how come some car works and other don't? Can you take the wires inside the car for the Voodoo mod instead of running them trhough the firewall? That was actually the main question of my first post.

thanks

puma

Napoleon

BRIAN_93.....6TH QUESTION....HOW DO YOU KEEP THE FAN FROM "STAYING" ON?
7TH QUESTION...WHERE/WHO MAKES THE BEST FAN?
8TH QUESTION....DOES THE "FAN SWITCH" (ON/OFF) COME WITH THE FAN, OR DID YOU PURCHASE SEPERATELY? (HOME DEPOT, LOWES, ETC?)
.......THANKS FOR THE TIPS COUSIN ......BIG NAP.

KevinK2

"ok so i why are other talking about a different wire if you can use the test wire?"

all that speak of 'test wire' refer to a loose wire, behind the ecu, with black and mabe another color on it. As I said, if you are lucky, as I was, this is the only wire you need to use. not all fd's are the same in this regard.


"ok but what if you close the switch before the 20 sec, will the fans turn off?"

for simple mod, the switch is closed to ground the test wire, for fans on. if on for 2 minutes before key-off, and then not left on another 20 sec after key-off, then the fans will turn off when fan switch is prematurely turned off, and no 10 minute run will follow.

"how come some car works and other don't?"

they are factory wired differently

"Can you take the wires inside the car for the Voodoo mod instead of running them trhough the firewall?"

I think the 226F wire switch goes directly to the fan relay, not the ecu. just check wiring diag. if u have had the extra recall relay installed, then this wire wcould also be accessed near the ecu, so the voodoo mod could be done there. don't know exact wires.

puma

iTrader: (2)

ok thanks kevin, you answered the questions i asked you.

As for the the 226, i have seen that it goes directly to the fan as you said but there is a "T" were the wire also goes inside the car on the EL CPU or something like that. Grounding it at the relay or somewhere in the "T" should have the same effect so i guess, we can ground it inside the car too instead of runnig a wire through the firewall and in the engine bay.

I will check tonight if i have the wire everyone is talking about. So you are telling me that the test wire is the same as the mod wire, that means that it will also have that female connector they are talking. If that's not it, i guess i am still confuse.

thanks

puma

puma

iTrader: (2)

can you help me on theses than?

"Third question: what happens if you turn on the switch before the fans started (because it wasn't hot enough). I suppose it won't do anything, the only thing that will happen is that when it will ask for low speed (when it getshot enough), it will get medium instead. Am I right? "

"Fourth question : I suppose this means that the fan mod won't help in turning the fan ON before the 221 deg of the low fan speed? Is that it? "

thanks a bunch, i really like to understand everything before doing a mod.

puma

puma

iTrader: (2)

anyone else can aswer the unanswered questions?

cewrx7r1

iTrader: (2)

Two more cooling mods that can be done for even more SAFETY. I replaced my 226F thermoswitch with the Miata 207F one. The fans come on 19 degrees sooner with this.

Since I have a PFC, I recently used a friend's DATALOGIT and changed the turn on points for FAN SPEED 1 to 91C and FAN SPEED 2 to 96C.

Now I only use the FAN MOD switch for post shutdown cooling.

CantGoStraight

Do you have apart number for the Miata thermo switch and is it a direct plug in for our harness ???