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Link AtomX - Wiring Issue - Relays live when ECU powered off.


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Hi guys, hope you can help, I've had a search but cant find the answer.

I'm new to the ECU (ATOMX), just busy setting it up on my car for the first time. I've wired it in as per the supplied wiring diagram. 

The two power relays are wired so that one powers the ECU and Injectors and the other supplies the coil. The fuel pumps and radiator fans have their own power relays - each has a separate fused live, switched live and the ECU triggers the ground pin.

Everything works as it should, injector and ignition tests are all good. sensors are all giving sensible readings.

Happy days!!

Until - if i pull the power fuse to the ECU so it loses all power but if the key is still switched to the ignition on position all the relays go live, the pumps and fans run. I've tested the trigger pin and it goes to earth when the power is killed. I guess I've wired a ground wrong somewhere but thought I'd ask if you guys know what I've done. Clearly I don't want fuel pumps running if there ECU lost power in an accident. 

Thanks Ashy.

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You should use the output from the ECU power relay (downstream of any fuse)  to provide the positive trigger voltage for the Ignition and Fuel Pump relays.  That way, when the ECU has no power, the relays can't be turned on.

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