I removed my ECU randomly and found that this plug doesn't have anywhere to go. Can anyone let me know if it should just be hanging there, or where it goes??
thanks a bunch

-Mike

oh by the way, the black box on the bottom is the Control Unit that attaches to the back of the ECU....the black connector is on the harness connected to the Control Unit.

 

That's what i ****** want to know!!! wooooh weird **** man! Only I wanted to know cuz i just did a tranny swap.

Although I do know it's for the water thermosensor I'm guessing you can plug a temp gauge into it either that or it's for the water thermo fan switch.

 

i think it should hook to that black box in the pic

 

nope only one plug goes to that.

 

if im correct if you ground it your fans will turn on

 

You are 100% correct.

That is the famous spade connector that you wire to a switch to ground.

Flip the switch on & the fans will turn on.

Keep the switch on for more than 2 minutes prior to shutdown & over 30 seconds after shutdown & the fans will continue to run (with the key out) for 10 minutes.

 

You are correct on the fan turn on wire. A little more help for me please . My 94 should run the fans for 10 min after key off and now that does not happen . I replaced the little black box and the the water temp sensors .I have not checked the relays . Any ideas?

 

That connector is part of Mazda's fan recall harness. The harness patches in between a blue and a white connector coming from the ECU harness, and includes the black box fan control module and that black test wire.

The fan recall also included a harness that goes between the fan relays and the wiring harness plugging in to them. That harness re-does 3 of the fan relays so they can operate with the ignition switch off.

The way the fan control module works is all by the water themoswitch at the back of the wtaer pump housing. Stock, the thermoswitch trips at 108 deg. C. This kicks the fans on. The fan control module monitors this circuit - if the temps stay at over 108 for more than 2 minutes while the car is on, it will trigger the fans to stay on for 10 minutes after the car is shut off.

This thermoswitch is the same one that many commonly replace with the FC thermoswitch, which kicks on at a much more reasonable 95 deg. C.

That black wire is simply to test the circuit. If you ground the wire for 2 minutes, it does the same thing as if the thermoswitch was tripped by high coolant temps. This way you can test if the fan control module is working properly.

If you get an HKS Fan Controller (http://www.clubrx.org/default.asp?id...ntent=41&mnu=3) you can tap one of the controller's fan outputs to that same black wire. You can then control the temp that the fan kicks on, and if it's running for more than 2 minutes you'll automatically get the 10 minute cooldown.

Dale

 

Wow invaluable info thanks so much Dale!

 

does anyone have a picture of this grounded??? i know its a stupid question, but i'd like to see it and be 100% positive i understand what i'm doing before i try something new on my baby

thanks in advance

 

let me rephrase that... can anyone tell me where i can find a convenient grounding point for this little doo-dad? does it have to go to a ground wire for some of the in cabin electronics or can it just bolt to the frame/body somewhere?

 

You can probably tap it with the other ECU ground that you have behind that panel.

 

https://www.rx7club.com/showthread.p...hlight=fan+mod
http://rx7.voodoobox.net/ (look under "How to")

 

Does anybody have the Mazda recall fan mod wiring diagram?

 

OMG just ground it, anywhere. I put my switch in the center console in between the fog lights and defroster. Used one of the mounting screws as the ground.

 

thanks. i wasn't sure about the grounding crap... sorry that i'm paranoid. why can't i find this sh*t when i search? i spent three days looking around for it... didn't even post anything for THREE DAYS! (which is a bunch for me) because i was trying to find this.

 

wrong thread lol.....good luck with the ground switch man

 

so... what gauge wire did you guys use for the switch? i'm thinking about like 24 but i haven't tested the Amperage yet either... i read through the scuderrriannanaini whatever page and didn't see it. i'm sure that since its controlling a relay, its probably only like mA we're talking about, but just trying to avoid a fire in my car... again with my paranoia

 

Um i used like 18 gauge speaker wire for the power and just like little 8 ga probly, wire for the ground.

 

16 or 14 ga. should be plenty and easy to work with.

 

thanks guys... sorry to keep asking stupid questions... but hey, at least i didn't start another thread right?

 

Good info here, thanks for posting Dale. My EMS controls the fans, and I had been wanting to get rid of that black box and harness. Ripped them out today and everything works as expected, no more fans running when the engine has turned off.

-s-