I have the factory manuals for our 1994, and the wiring diagram on page Z-40 shows that the only way cooling fans can run, with the ignition OFF, is if the contact set of Fan Relay #1 is shorted. However, I understand the cooling fan recall done on this car added the capability of running the fans if the underhood temperature is too high regardless of whether the ignition is on or off.

The fans have suddenly (at 82K miles) developed the habit of running for long periods of time (>10 minutes) after shutting off the engine even when the temperature gauge indicates below "9:00," i.e. below horizontal. Sometimes restarting the engine, then shutting it off, will shut off the fans, sometimes not. I have the feeling this may have something to do with the recall fan controller circuit, but I know neither where it is located, nor how it is wired up, nor what is inside.

Is this information available somewhere?

Thanks for your time!

---- Bill

 

This behavior is possible IF your car has the updated cooling control, andCheckout the attached schematic and control table for more details.

Also note that the temperature switch is NOT the same sensor that feeds the temperature gauge NOR is it the same temperature sensor used by the ECU; these are 3 separate devices.

P.S. - My understanding is that w/o the updated fan control the fans will NOT stay on with the ignition off because on these vehicles the fan's battery power is switched off by the ignition switch curcuit. The curcuit is shown in the FWM.

 

Somehow lost the second image.

 

FDjunkie,

Thanks very much for that helpful response. The FWM wiring diagram shows the fan motors having two sources of battery power, and two separate grounds. However as you wrote, the ignition switch is required to be ON for either motor winding to receive power. In your attached diagram, not only are the relay contacts powered from the battery, bypassing the ignition switch, but also so are the "hot" side of the relay coils, meaning the only thing required to fire up the fans is a return to ground on the cold side of relay #2 or #4. And that seems to be controlled by the state of terminal "E" of the "Cooling Fan Control Module."

Do you know where the "Cooling Fan Control Module" is located, and where in the wiring harness the change in the power source to the relay coils' hot sides was made?

Again, thanks for the very helpful schematic and possible sources of this problem!

---- Bill

 

The updated fan control module is mounted behind the ECU in the left side of the passenger's footwell. On '95 it's attached to the ECU as shown in the locations pdf.

I assume that the updated fan controls must have replaced some portion of the front wiring harness; at least that section that connects to the fan relays. Some time back I helped convert the wiring on a friend's pre-update '94 FD. We spliced the wiring right at the relays as shown in the attached picture. This worked well with his manual fan speed control.

 

Dah, that's the right side of the passenger's footwell...

 

FDjunkie,

Thanks once again. They hid that fan control module pretty well!

---- Bill

 

Wiring an aftermarket fan and would like to use the existing fan wires. There are 5 different wires attached to the 2 fan motors; 3 in common and one unique to each fan. Anyone know what each of these are? Would particularly like to tap into the AC relay wire.

 

anybody know the part number to all the parts in the cooling fan recall ?

Thanks!

 

Read my posts on fan control, I typically throw that whole system out. A properly running FD doesn't need that system.

It was a hack Mazda did to bandaid the system, the real fix is having your coolant system run at a reasonable temperature.

Dale

 

I already read ur post, it's a great read and I know how this system works inside out, my first car was RX-8 and it's even better.

but I'm just curious of what part is involve so I can check my friend's car to see if his car has it. I found the fan control module part number, but nothing about the harness

 

There's really only 2 parts, a harness that plugs in between the fan relays and the wiring harness and the control box and wiring that plug in by the ECU. The ECU side wiring has wires that plug in between the blue and white plugs going to the ECU and a ground wire.

Most FD's have had the fan recall done, this was a recall that Mazda sent letters out and had owners bring their cars in. I don't think I've ever seen one without it in place. I have seen many FD's that I've ripped that system out of, though .

Dale

 

but do you know the part number for the said harness ?

 

I think the recall was N3A1-18-SEO, contact Ray.

 

Thanks!