The Stovebolt Site Forums The Parking Lot Big Bolts How to wire a Tach

Hi I have recently aquired an old tach that I want to install on my 57 chevy 6100. When I got the truck It had a big hole between the light knob and the choke knob. It looks factory because of how precise it is cut. See the tach fits in the hole and thats where i would like it.
Now heres the promble i don't know how to wire it. Win I tried to wire I got shocked . But I have kind of figued it out. Theres to nuts marked one says B+ witch I assume means postive on batter. The second has an S+ witch means starter right? But I dont know what the other two are for. Please help don't want to get shocked again. Thank for any info

I would connect the B+ to the ignition switch, so it's powered with key switch on. There is no value in feeding it with live battery power
I would connect the S to the points wire post on the Ignition coil. To me S means signal. Signal is provided by the points "pulse". 4, 6, and 8 cylinder are different, certain resistors are used to make the tach read correctly.
The case should be grounded.
There may be a connection for a light.

OK I guess I should of also of said that it doesnt have no points. It's electric egnition. Sorry for not including it. I think the gauge is from the 60s I think.

disconnect the battery when you are wiring.

I think there may be a converter that will take the electronic ignition and give the correct signal to your tach. I think I just saw it on My Classic Car last week on their Eastwood Garage or Egge, what ever they call it.