On an oldsmobile cutlass supreme (1989) why does it say to disconnect the negative battery terminal for the back three plugs? The side mounting battery terminals are difficult to access and none of my socket wrenches fit in that small space. What could go wrong if I skip the step of disconnecting the battery?
Why do you have to disconnect the negative battery terminal when changing the back three spark plugs?
you can get a power surge, spike, get a good shock ect...
Why do you have to disconnect the negative battery terminal when changing the back three spark plugs?
I don't know the car, but my guess is it's a safety precaution, either to protect the electronics in the car or prevent the mechanic from getting an electric shock. I suspect this is one of those cases where some foolish person got an electric shock and then sued the manufacturer. I can't see why you couldn't just disconnect the positive terminal, but personally speaking, it never occurred to me to disconnect either when doing spark plugs. You should remove the car keys from the ignition before starting just to protect yourself. If the battery terminals are within range of the socket wrench, I would ensure they are covered as a precaution.
