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MG MGA - Battery Disconnect Switch Install

I'm about to replace my battery with one of the new "dry" types and plan to install a disconnect onto the battery at the same time. I've received varying opinions on the proper install of this switch: Some have told me to install on the ground side while others have told me to install on the hot side of the battery because my car is still positive earth. Any electrical engineering types who can set me straight on this?//nk
N Kopernik

I'd switch the polarity - there's no good reason to stick with the +ve earth except for the quirkiness factor, and switching to a "standard" modern setup prevents the innocent error of a towman or mechanic ruining something.

Then wire the cutout into the +ve side
dominic clancy

My challenge is that I did not think of switching polarity before I installed a new electronic fuel pump 2 years ago and recently installed a solid state distributor as well. Not sure if the distributor is an issue, but I know I would need to switch out the fuel pump. And besides, I have a Lucas 8-track tape player in the car and it is positive ground as well, so I'm stuck until the next major refresh of hardware.//nk
N Kopernik

You would install the switch on the "hot" side. With a positive earth the switch is on the negative side of the battery.
In fact it does not really make any difference, as a switch on either side isolates the battery and a short circuit, or any other problem, cannot occur as a current flow cannot pass through the battery.

Mick Anderson

This thread was discussed between 21/07/2008 and 23/07/2008

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This thread is from the archive. The Live MG MGA BBS is active now.