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[boscoe99]

A short by definition (I think) is a direct path for positive current to flow to ground. With little to no resistance limiting current flow. A short IMO will cause some bad stuff to happen if a fuse/CB does not protect a circuit. As in, it might let some smoke out of the wiring insulation.

Some Yamaha equipment is turned on by the application of a ground. But let's say a normal ground is not applied but rather a ground wire gets chaffed to a ground point. Nothing bad necessarily happens, maybe the component is just powered up as it would be if an ECI applied the ground.

Is this what any of you would refer to as a short in the system?

[rodbolt17]

say we are working on an OX66.
say someone installed the VST after maint.
say the blue pump wire got pinched between the intake and the washer.
pump simply runs anytime the key is on.
did not hurt anything.
no I did not do it, a former employee did.
yes it was shorted.
however it is designed to be shorted.

now when an isolator lead got pinched it blew an 80 amp fuse.

[DennisG01]

For me, I guess it depends on the scenario or the way the word is used in a sentence. For example:

- To check if the pump was operational, we shorted the positive and negative directly to the battery... In this way, it's good thing.

- There may be a short in the system since it (generally speaking) does/does not work... In this way, it's going to require A LOT more trouble shooting to find the issue - in other words, a "bad" thing

I suppose it's a lot like saying: "I'm looking at the engine but can't find the fuel pump. Is it on the right or left side?"

[99yam40]

Boscoe I think you have a good definition of a short there.

maybe if the negative side gets a parallel path to ground it would be called something besides a short.

as long as the resistance of the load is there and it is meant to be able to run constantly it should not hurt anything,

but if it happens to something like the IAC/ISC which is supose to only be intermittent service, then it will probably heat up and destroy the circuit the ECU is furnishing to operate that.

Dennis, I would say you do not short the +&- of the pump to a battery, you would jumper them directly to the battery

[cpostis]

My Definition of Short Circuit:
When the path of current is diverted from the intended path to another path that is not intended.

Of course, the current will follow the path of least resistance. 99Yam, in your statement of parallel path, I would still consider this case to be a short.

I had my engine mounted t/t switch weld closed when unintended. In this case the current did follow the intended path, but not when it was intended. Therefore, the switch was shorted. This happened while underway at about ¾ throttle. First sign was my boat veered to one direction, then the increase in rpm and noise. Luckily, I was in the open ocean.

In the example the Rodbolt stated, If I understand how the ECU controls the VST Pump correctly, the con*****ing medium of the ECU has been by-passed (shorted). In my OX66 motor, when the ignition switch is turned to on, the ECU closes the negative lead from the pump to ground. The pump runs for several seconds to pressurize the fuel rail then shuts down per the ECU until the engine is started or the key switch is cycled off then on again.

Say, for some stupid reason, someone left the ignition switch in the on position without the engine running, and the negative lead from the pump was shorted to ground. The pump would continue to run, the fuel will recirculate through the pressure regulator, the fuel will heat up, and the pump motor will overheat and possibly fail, or even worse cause a fire?

All kinds of weird donkey manure can/will happen due to short circuits.

[99yam40]

maybe a short would be the unintended connection of a circuit.

But in the past I always looked as a short as something that caused a non intended connection that quickly tripped a breaker,blew a fuse, or melted wiring or its insulation by drawing more current than the circuit was designed to use or carry safely.

there was grounding of circuits or partial grounding on the neutral or negative side also.

But if it took out a power source then it was shorted in my mind.

a lot of ways to look at this I guess.

Bosco You need to redo the title from delete