Thread: Which battery disconnect switch?

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Should I use a 4-post switch, or one of the fused memory guards on a 2-post switch? I want to retain the clock and radio settings when the switch is in the disconnect mode. I see that NHRA requires a 4-post switch for use with alternators. I don't know what that does, but I don't need to meet any NHRA requirements. Thanks.

Originally Posted by roofcam

Should I use a 4-post switch, or one of the fused memory guards on a 2-post switch? I want to retain the clock and radio settings when the switch is in the disconnect mode. I see that NHRA requires a 4-post switch for use with alternators. I don't know what that does, but I don't need to meet any NHRA requirements. Thanks.

NHRA wants something more than a battery "disconnect switch".

What they require is a battery "kill switch", that will shut off the engine even with the energized alternator turning. You can wire a two post cut off switch to do this if you pay attention to which terminal side you have the alternator wired into.

John,

I guess I didn't word my request very well. I don't need to meet NHRA requirements. I just noticed the NHRA requirements when looking at switches. I just want a switch that will disconnect my battery, while maintaining enough power to not kill my clock and radio settings in my rod. My battery is in a spot whereby it isn't too easy to remove the cables when working on the car.

Thanks for the response.

I use a 2 post with the memory guard mounted in the trunk of my Model A. My battery is also difficult to reach since I upholstered my trunk. Works well. I have it in storage now or I would send pics.

Pat

By the way, here is the URL for Speedway that handles the memory guard.

http://www.speedwaymotors.com/p/2383...ectronics.html

Thanks, Pat. I think that is the way to go.