not really good with wiring, so where exactly can I pickup the 12 volt ignition hot wire from and the illumination wire for light of my autometer 5" tach , need to know exactly where I can hook these wires at, have a 1990 Mustang GT
Hi,
No problem. You have a 3 or 4 wire Tach & what model # is it? Have a shift light?
In the meantime, mount your Tach where you want it to be. Switch in rear (4-6- or 8, set to 8) Get the wires close to the locations, below, don’t cut them just yet.
1) Locate a firewall penetration where there’s other wiring passing through. Pass the Coil wire through. (It’ll attach to the Coil’s NEG(-) terminal using the supplied ring stud connector.)
2) Using a multimeter in DCV mode, locate a switched power point within the fuse block inside the car, energized with Key in ‘Run’ position.
(This will attach to the fused Tach “Pwr” Wire).
3) Ground. Whatever’s easier to locate for you. You can land it on an existing ground wires bolt.
If you see a ground wire under the dash, there. If going to the engine compartment firewall Is easier- send it through the firewall with the first(Tach) Wire.
4) Locate the wiring on the back of your light switch. Want the Tach. to dim with the stock dash lights, or just want it to illuminate when you turn the lights on?
I’ll respond back with specifics when I know which model it is. Ones a 3 wire, ones a 4.
TTYL
-John