That should be DPDT switch. You can think of it as two separate SPDT switches that are operated simultaneously by the same actuator. Each switch has three contacts. The top contact is for one position of the switch, the bottom contact is for the other position of the switch, and the middle contact is common.
Without modification, this flasher will only work on applications with positive-side switched headlight systems. Cut the positive wires leading to each high beam and extend them to the switch.
- The extended wires leading to the high beam lamps should be connected to the common terminals of the DPDT switch.
- The extended wires leading back to the dimmer switch should be connected to the top terminals of the DPDT switch.
- The L terminals of the flasher should be connected to the bottom terminals of the DPDT switch.
- The X terminal of the Tridon EL13 should be connected, through the 10-amp fuse to the battery's positive terminal or another suitable source of +12v DC.
The DPDT switch connects the high beams either to the flasher or to the dimmer. The flasher will start to run when the DPDT switch is switched to completes the circuit through the high beams and will stop when the DPDT switch is switched back. Because of this design, this flasher provides no high-beam override function.