aftermarket tach- best place the hook the hot wire?

65 coronet (slant six) . looking for best place and method to hookup the hot wire. i know instructions say to hook to ign run , jsu wondering best place to do this and best method other than hacking into wire???

barbee6043 said:

65 coronet (slant six) . looking for best place and method to hookup the hot wire. i know instructions say to hook to ign run , jsu wondering best place to do this and best method other than hacking into wire???

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I have installed several aftermarket tachs and the "run" wire is usually green coming from the tach and should be hooked to the negative side of the coil. The red wire from the tach goes to a "keyed" "hot". That is, a wire that carries current only when the key is turned on. Hope that helps. wire.

barbee6043 said:

65 coronet (slant six) . looking for best place and method to hookup the hot wire. i know instructions say to hook to ign run , jsu wondering best place to do this and best method other than hacking into wire???

Click to expand...

Hook it to a keyed circuit behind the fuse box. Just be sure it's 'after the fuse', not before it. And make sure it's not the dimmer circuit for the dash lights. Mine had some empty spades but you could just add a spade splitter like this...



The way to test is this - check voltage at the fuse with key on and off. Then check voltage with dash lights on, off and partially dimmed - the dimmer circuit cuts voltage to dim the lights and will wreak havoc with the tach if you connect to it. Pick the circuit with constant voltage obviously.

thanks for the tip.