Car wiring diagrams: 3Pdt Switch Schematic Wiring Diagram, wiring diagram, wire wiring harness, schematic circuit diagram, wiring diagran, wireing diagram, wirring diagram, wiring daigram, wiring diagrams. The PDT switch triple pole, double throw allows you to modify your effects for true True bypass conversion for printed circuit board effects diagram .Before going any further, you have to understand how functions a PDT footswitch. Here is a diagram showing the different possibilities to a simple on off switch simple pole dual throw SPDT equivalent to a toggle switch. and output jacks are directly connected, the signal does not goes through the circuit bypass .Here s a wiring diagram for options of battery or DC jack power Adding an LED to the non true bypass switching requires a DPDT switch. An example of a buffer in the circuit of a non true bypass stompbox can be seen in the original .