Tach Wiring

[98Dak408]

I’m in the process of wiring a no frills Autometer tach in my 1998 Dakota. I have 4 wires:

Black = ground
Green = neg. coil
White = head light on
Red = ignition on

Black is a no-brainer. White is going to the lg. light green wire from the headlight switch. Red is going to the lg. blue wire from the ignition switch. My question is where is the best spot to tie into the negative coil wire? I’d rather not route it all the way to the coil. I may try to find the wire at the ASD or factory tach.

Anyone with any knowledge or suggestions on this?

[98Dak408]

I ended up running a wire to the negative coil terminal. In the jungle of wiring under the hood, you can't even tell it's there.

I hooked the white wire up the the lg. green wire of the headlight switch and the tach lights when the headlights are on but not when just the running lights are on. I'm going to have to search for the correct wire that works with both the headlights and running lights.

[Rebel13]

I just added a tach to mine. Took a while but, found the right wire. You need to run it to the orange wire on the HAVC panel. This is the one controled by the dimmer switch.