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I’m hoping you guys can just give me a quick sanity check on my wiring setup for my Holley ECU. I’m mostly confident that it’s solid. I just want to make sure that there aren’t potential areas that I may be overlooking before I do my first start up.
I put together a quick diagram with how I currently have everything wired.
It’s basically battery positive going to a blue sea fused panel with a main input lug and separate fused output lugs. Battery negative to chassis ground and engine block. Ground bus with input lug from chassis ground and separate outlet lugs for ground. I have the ECU switched power wire going to a relay. The relay main power is fed from the input lug of the fused panel, relay ground to the ground bus, device power to the ecu switched 12v wire, relay coil power to one side of an ignition toggle switch in a switch panel, the other side of that switch goes to a fused output on the fuse panel.
I have the transmission cooler fan setup the same, just on a separate fused circuit on the fuse panel and a separate toggle switch on the switch panel.
i have the alternator excite wire with 470 ohm resistor going to the same side of the ignition toggle switch as the ecu relay coil power wire so that the ignition switch also excites the alternator.
if all of this looks right, I’ll start on the transmission harness and wire it the same, using separate fused circuits on the fuse panel.
Also, for clarification, this is for the Holley ECU 12v switched wire, NOT the main power for the ECU which I have connected directly to the battery pos/neg.
yes, that looks right to me. do you want to be able to run your transmission fan when the ignition toggle is off? you could wire 12v from through ignition toggle through the trans toggle if you didn't want to turn the trans fan when ignition is off.
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Holley Terminator ECU Wiring 
