Battery Cutoff Switch best position

[WHSEWARD]

I have looked through many sources on the Internet and have gotten conflicting views, on where best to place the battery cutoff switch in an antique car.  First, some history.  On my 39 Buick I had a dead short to ground and only saved the car from a fiery death because I was able to reach and turn the cutoff switch, which was on the POSITIVE side (negative ground car).  On my 31 Lincoln I had a cutoff switch installed, but it was on the NEGATIVE side (negative ground car).  That switch has now failed and I need to install a new one.   The preponderance of opinion seems to be that the cutoff switch should be installed on the ground side, but I do not see how this prevents a fire in the case of a dead short in the wiring, such as I had on my Buick.  In my particular case essentially all of the circuits in the car are grounded to the chassis at individual points in the circuitry, so it seems to me that a short to ground would still feed all the power from the battery to the ground short even if the cutoff switch were installed on or near the negative terminal of the battery. I would appreciate some discussion and opinion on this.  Thanks.

[Owen_Dyneto]

Best practice is use the switch to break the ground cable.  Put the switch where it can be easily reached, preferably without opening the seat.  For cars with batteries under the front seat the locations of choice are on the seat riser between the driver's legs, or on the front floor board just ahead of the battery, again between you feet.

[joe_padavano]

Putting the switch in the ground cable prevents a short because it disconnects the battery ground terminal from the frame and metal body in the car.  This way, any hot wire shorting to metal will not close a circuit unless it is shorted directly to the negative battery terminal.  In addition, if the switch is on the ground side, a metal tool dropped onto the battery against the positive terminal won't short to ground.  If the switch were on the hot side of the battery, the dropped tool WOULD short to ground and sparks would fly.  While I understand the desire to have the switch accessible while driving, it is most effective if it is mounted directly to the ground terminal of the battery, as this minimizes the exposure of wiring that is not disconnected by the switch.

[Phillip Robinson]

I have recently put one on the battery, earth terminal. It screws down to allow for contact. I find it to be easy and worry free . It just mounts to the terminal and allows you to connect earth cable to it. Phil

[alsancle]

I put mine on the floor board center below the front seat,  simply reach down and switch it.  Putting on the chassis, or under a fender is a pain in the rear.