ECM pin out for fan control?

[YGETV8]

I tried searching, but can't find a list of ECM pinouts, or more specifically, the pin out for radiator fan control. My Hybrid RX7 must still be controlled by the Mazda settings as the fan does not turn on when DirectScan says it is signaled to. It comes on at a much higher temp and keeps my car a nice cool 208* in this summer heat! I bought a Hayden adjustable fan control, but the Taurus fan it has must pull tons of amps cause it overheats the controller and 30 amp relay! Too bad, 'cause for a while it was able to keep it around 180*. I didn't think that was too bad for A) small frontal area, B) not much room to vent the moving air, and C) a front mount IC.

I plan on finding the pinout and wiring it directly to the fan relay (after I find it, too!). Thoughts?

Thanks for any help. Jay

[TurboDave]

Sounds like the only thing triggering your fan is the high temp switch. That's the one mounted on the intake, driver's side, verical mount, one wire.

Lo spd fan control is on D2 (dk grn).

Ecm doesn't appear to have a high speed fan control, so that signal must be coming from another source.

There's an A/C clutch control that comes out on A2 (lt grn/blk). I wonder if that also triggers the high speed fan relay? I'm at work and don't have the wiring diagrams in front of me to verify that.

[pacecarta]

D2 is for low speed fan control , its not power, its only a ground for the low speed fan relay ,

the A/C pin at ecm is for 12v in, its for telling the ecm that a/c is requested to be on so it can adjust the base idle rpm
the high speed fan is turned on with a/c but its done via a pressure switch on the pressure line behind the a/c compressor , if A/C sytem is on and operational ( charged) the high speed fan is engaged

[TurboDave]

Originally Posted by pacecarta

D2 is for low speed fan control , its not power, its only a ground for the low speed fan relay ,

That was the OP's original question, "fan control".

the A/C pin at ecm is for 12v in, its for telling the ecm that a/c is requested to be on so it can adjust the base idle rpm

You're refering to pin B8.
I knew that, that's why I didn't direct him to pin B8.

But thanks for posting the schematic, that'll make his search much easier.

the high speed fan is turned on with a/c but its done via a pressure switch on the pressure line behind the a/c compressor , if A/C sytem is on and operational ( charged) the high speed fan is engaged

[salvageV6]

The Ferd fan draws about 40A inrush current maybe a tad less to run it.

I ran a second 30A relay in paralled with added wiring to it to the factory high speed 30A relay.

If the controller uses a relay 30A internal or external that would be the only thing that should heat up in it if it's installed properly with heavy gauge wiring 10 or so to run the fan circuit.

Controller wiring etc. should be separate fromt the high current relay stuff.

Relay would just cook the contacts a bit with overcurrent, and then go open cirucit and not work at all and stay cool.

Double check your wiring and make sure you add a good ground for the fan to work with, 10 gauge to the battery.

[YGETV8]

Thanks for the replies, guys! My use of the terms "ECM" and "pinout" pretty much wraps up my electrical knowledge, so any info is useful. But, given what you are saying, maybe it'd just be easier to use the Hayden adjustable control output to trigger the high speed relay?

Speaking of, it came with pretty wimpy wiring and after a few days use, it started intermittently cutting the fan off and on and was very hot to the touch. I'm sure it's more than maxed out on a >30 amp fan.

Thanks, Jay

[salvageV6]

A relay like this would work well triggered by the Hayden controller.

eBay Motors: 2 Nos 70A 70 amp 80A 12V Auto POWER RELAY Relays 4 Pin (item 150271357189 end time Jul-22-08 06:44:09 PDT)

However I posted this for technical reference as to what to look for, I wouldn't buy from someone located in India with such poor feedback.

Search for a 70A 12volt relay and you should be able to find one.

However the wire holding "blades" are usually larger for the connectors to go to it and might be hard to find locally so if you find one and can get the connectors for use with 8-10 gauge wiring with it buy some.

I have a NTE made 12 volt relay that handles the current but haven't used it yet but it does have substantially larger blades on it.

Don't hook the hayden up to just trigger the factory high speed relay it will cook as well over time.

[YGETV8]

Originally Posted by salvageV6

Don't hook the hayden up to just trigger the factory high speed relay it will cook as well over time.

Not sure I follow this statement as the factory wiring is and has been running the Taurus fan for quite some time now? If I used the Hayden controller 12V output to be the trigger wire, that wouldn't change the amps currently (no pun intended!) going through the factory wiring, right?

Thanks for the info, though. Yeah... that cheap India relay kinda scares me!

[salvageV6]

You running the fan on high speed with the stock wiring and relays?

[YGETV8]

Yes, the factory wire that is controlling on/off is going to the high speed wire on the fan. I installed a 10 gauge ground right from the fan when I discovered that it was such high amps, but it had been using the factory wiring also.

[YGETV8]

You were very helpful in your responses to my post about fan wiring, thank you! The only thing I tried was tying the Hayden output to the high speed relay input. There must be other factors that do not let the fan kick on till higher temps because it still didn't kick on till about 203*, despite my adjusting the controller. The factory fan relay input control wire was brown, and there is another smaller wire that is green. Is this the relay ground and is it controlled by another source which is only completing the circuit at 200*+? If so, can I just run it straight to ground leaving only the Hayden to control the system?