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Another senior moment

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CaptRandy

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If there is a draw on battery with engine off, lights off, etc, will I only see an arc and spark when I disconnect + cable or will it also happen with the - cable? Negative ground car.
 
The answer to your question is YES If there is a draw on battery with engine off and all accessories.

A modern type Radio with a memory might be the exception here.
 
You will get an arc/spark from which ever pole you disconnect first, and as Keoke points out, only if you have a load on the system. You will also get an arc when reconnecting, even if no load, as the battery charges the capacitance of the wiring/system of the car. It won't spark again if you disconnect/reconnect though since you've already charged the system, unless there is a load on the system like the newer radios which syphon a little off the battery to keep the memory/etc. energized.

hope this helps, having problems??
 
No, just when pulling off negative cable today experienced no arc/spark and wondered. I do know for some reason in the past it was always advisable to pull neg first but can't remember why. When I say in the past I am thinking 50+ years ago when I first learned that.
 
The school of thought is to pull the "ground" cable first to prevent arcing. The arcing in this case is if your wrench were to slip and hit a metal portion of the car while still connected to the battery terminal. It would not spark at all if you did this on the ground cable. "Ground" could be positive or negative depending on how our cars are set up, so don't get into the thinking that just the negative cable is the safest to disconnect.
 
healeyblue said:
The school of thought is to pull the "ground" cable first to prevent arcing. The arcing in this case is if your wrench were to slip and hit a metal portion of the car while still connected to the battery terminal. It would not spark at all if you did this on the ground cable. "Ground" could be positive or negative depending on how our cars are set up, so don't get into the thinking that just the negative cable is the safest to disconnect.
Click to expand...

:iagree:--------Spot on !!
 
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