This 4 position, fan switch will run your 3 speed heater fan without complicated relay wiring.
It also has a live out terminal for a warning light or control system. Rubber knob, with fan symbol.
Wiring Connections C-Live feed to switch, L-Speed 1, M-Speed 2, H-Speed 3, B-Live out in any on position (e.g on warning light)
Note: Your motor must have windings for three speed operation.
3 SPEED FAN SWITCH #SWFAN