Msd Tach Adapter Wiring
Run enough wire to reach the msd ignition control box mounted on the firewall in the engine compartment.
Msd tach adapter wiring. Once the wire has been located it is recommended to check for 12 volts using a volt meter. The tach output terminal produces a 12 volt square wave signal with a 20 duty cycle. 7 for wiring and tach adapter information. Voltage triggered and current triggered.
The auto meter tach adapter wires in line on the positive 12 volt supply wire. Spark plugs and wires spark plug wires are very important to the operation of your ignition system. If your tachometer doesn t work correctly after installing an msd ignition control always try to connect the tach s trigger wire directly to the tach output of the ignition. Voltage triggered and current triggered.
If the tach still registers incorrectly install this tach adapter. The pn 8920 will correct the operation of most voltage triggered tachometers that do not work directly off the tach output terminal of the msd control. It is recommended to have a wiring schematic of your vehicle s ignition system to clearly identify the coil positive 12 volt supply. A good quality helically wound wire and proper routing are required to get the best performance from your ignition such.
We drill a new hole and run the wires through the firewall below the starter solenoid. Mount the tach adapter in a location away from direct engine heat making sure the wires reach the msd unit and the coil. Figure 1 wiring the tach adapter. Some vehicles with factory tachometers may require a tach.
To install the tach adapter the coil positive wire must be identified for your application. This terminal provides a trigger signal for tachometers a shift light or other add on rpm activated devices. If your tachometer doesn t work correctly after installing an msd ignition control always try to connect the tach s trigger wire directly to the tach output of the ignition. Fit new wire from the female female connector and run the wire directly from the spool through an open point on the firewall.
Strip the end of the trigger wire for the tachometer and place a female to female connector to it. Splice the white wire from the pn 8910 into the msd s white trigger wire. If you are using the magnetic pickup input green and violet wires to trigger your msd ignition you will need the pn 8920 tach adapter. There are two style tachometers that may have been used on your vehicle.
If the tach still registers incorrectly install this tach adapter. There are two style tachometers that may have been used on your vehicle. It senses current on the coil positive wire and converts it to a 12 volt signal output. The auto meter tach adapter wires in line on the positive 12 volt supply wire.
Vehicles originally equipped with a cd ignition control cannot use an msd.