RX7Club.com - Mazda RX7 Forum - Engine Fuse Keeps Blowing

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Does the ecu need to be plugged in to check for power/grounds with a logic probe? The ecu just sends a signal and doesnt send power through the plugs im checking correct?

Quote:

Originally Posted by Andre Fung (Post 11424051)

So the wires should have no resistance? If they have some or infinite they are open/shorted? That being said are the black white wires power wires? With the power and key on and fuse out, because it will blow, with the emission harness i believe the short is in unplugged from the ecu, the black white wires at the plugs are showing ground versus power. I'm using a logic probe. Does that mean they are being affected?

The B/W wire from the Engine fuse are power wires w/key to on an that is why they are connected to the fuse. They should not have high resistance to them. And when conducting an ohm test there is to be no voltage going through the wire or you can damage the circuit thus the key is always off.

Quote:

Originally Posted by Andre Fung (Post 11424054)

Does the ecu need to be plugged in to check for power/grounds with a logic probe? The ecu just sends a signal and doesnt send power through the plugs im checking correct?

Depends on what wires you are measuring as some wires to the ECU are input wires and some are output.. And you need a multimeter to find the short ( think ohm test).

I have a relocated battery in the boot. But i have a positive terminal at the front to run everything off so it is a posible you are completely right. I had never thought of that. Thankyou for thinking outside the box. I never thoight of that 😂😂👍