Power vs. Ground side switching

[Mike Agostino]

I know etgc and scanner danner did a video on this but why is it important to know and why would it be beneficial to know this when diagnosing?

Topic

[college man]

so you don’t put power to a ground side or vice versa and fry electronics. It gets expensive
to replace ecm or other critical components. :cheer: Then you have to explain it to the boss
or customer. :pinch:

[Mike]

You would want to know what to expect when checking terminals. You maybe find that a component has power but no ground and start worrying that it doesn’t work because it’s not grounded, but it’s ok because the component is switched on by the PCM supplying ground to it as opposed to being always grounded and supplied power when intended to operate.

As College Man said, you also want to know how power and ground are supplied if you are trying to test things by supplying power and/or ground manually. Rarely will hooking power and ground up to a solenoid, bulb, or fan motor backwards do any damage, but more computerized parts get sensitive. You want to be in the habit of flowing electricity through anything/everything in the intended direction, which is typically depicted in factory wiring diagrams.

[Author]

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