A Tel-Tac tachometer measures an engine's revolutions per minute, or RPMs. One feature of a Tel-Tac is that the tachometer records the highest RPMs during a single driving session and then displays the reading for 30 minutes after you turn off the engine. Because of this, the tachometer is often used in racing applications. However, the Tel-Tac works on just about every motor, even those that use a magneto for timing. The installation process for the Tel Tac tachometer is straightforward.
Things You'll Need
No. 10 Drill Bit
Place the mounting template provided with the Tel Tac on the dash or in a place where it is easily viewable but does not block any other gauges that you must see. Mark each mounting hole located on the template on the dash.
Drill the mounting holes into the dash with a No. 10 drill bit.
Drill a 1-inch hole into the dash to feed the wires from the tachometer to the engine compartment.
Mount the tachometer to the dash with the 10 to 24 self-tapping screws provided with the tachometer and a screwdriver.
Attach the black wire that extends from the dash to a grounded source on the vehicle's frame. If necessary, drill a hole in a grounded piece of metal and secure the wire to the metal with a self-tapping screw. If possible, remove an existing bolt and secure the wire between the bolt and the mounting surface to which the bolt attaches.
Locate the coil in the engine compartment. To do this, locate the distributor cap with all of the spark plug wires connected to it. The wire in the center of the cap goes to the ignition coil. Locate the black or negative wire on the coil and remove the nut that secures the wire to the coil. Place the white wire from the tachometer on the threaded stud or bolt from which you removed the black or negative wire. Reinstall the red wire and tighten the nut. If your engine uses a magneto instead of a coil, secure the white wire to the points terminal on the magneto.