Rev counters have at least 3 wires:
- The 12V wire: usually its colour is RED and carries a 12V voltage to power the rev counter. It does not power the light of the rev counter though. In a real car it would be connected to the ignition switch but we connect it to the + terminal of the board (see photo).
- The ground wire: it is BLACK and it should be connected to the battery ground. We connect it to the terminal with the – (see photo).
- The coil wire is usually BLUE and should be connected to the ignition coil. This wire carries the information about the engine rotation speed. Must be connected to the S1 terminal (see picture).
- Terminal S2 on the Rev Burner’s PCB is not used at the moment.
It is likely you rev counter has a backlight which is supposed to turns on when the car lights are turned on. In this case you will find:
- Another wire for the 12V which is usually connected to the light switch of the car. I found this cable is often WHITE or YELLOW. Connect it to the + terminal, together with the RED wire seen previously.
- You may have a second ground cable. If present it is BLACK. Connect it to the – terminal.
So basically you have 1 or 2 pairs of wires to connect to the 12V and the ground, and the wire supposed to connect to the coil, which we connect to the S1 terminal.
There is no switch for the rev counter backlight. It is always on when the power supply is connected to the board. If this annoys you, you can connect a switch inline with the wire carrying the 12V for the backlight.
