Bypassing the Amp gauge - Question about the MAD Electrical method

Xtreamist said
The last time the PO had it running was just over 2 years ago, it has sat ever since, he was battling cancer and lost. I'm not sure what all he did to it but I'm slowly figuring it out.
I'm thinking the tach switch was just for the lights? I am fine with relocating it but I have to have it. I agree with you about using the ignition switch and relay the way they were designed to be used from the factory. Seems it would be less complicated.
I will need a cut-off switch since the battery is in the trunk per NHRA rules.
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The tach needs a power source to amplify the signal and move the needle. If its a fancy tach it will need power for the light, memory or whatever its got. I just can't think of a reason why it would be on a seperate switch.

Battery cut-off is straight forward. Battery cut-off with engine shut-off is a bit more complicated. Last time this came up we talked about having the switch ground out the engine side or using a relay.