Mustang Boards - How To: Install Tach Adapter

Ok, Everybody gets confused with the wiring of this gadget so ill clear it up...

If you have an MSD or an Autometer adapter then this is how you do it.

Installation under hood:

1. Disconnect the battery.:shifty:

2.Find the MAIN HARNESS. It is located Top side of engine, passenger's side, and near the firewall.

3.Unwrap the factory tape that holds the bundle of wires together. Make sure you have tape to wrap it back up with. pull the wires gently out of the wire loom.

4. MSD and Autometer's Instructions say to use the WHITE/BLUE wire. But I and others have tried that with no success. It just didnt work with that wire. I found that I needed the large solid RED wire.

5. Cut the large solid RED wire and splice the 2 ends. Splice both wire ends coming from the tach adapter.

6. Solder the Solid RED wire from the Tach adapter to the large solid RED wire coming from the Main Harness. (Use a shrink wrap or at least electric tape to wrap all the connections.)

6. The RED/GREEN wire coming from the tach adapter needs to be soldered to the large solid RED wire leading to the engine coil packs.

7. Then find a common ground somewhere for the tach adapter. (i just use some random bolt.)

8. From there your signal wire coming off the tach adapter should be connected to the device you plan to use (window switch,shift light..).

9. Clean up all connections and make sure tha no wires are showing and that you put all the wires back in the wire loom and wrap it back up. Come on dont skimp out now....:nono: .

10. Reconnect the battery.

11. Now all your window switches will work and your shift light will work. It makes shifting so much cooler with a shift light.:beerchug: