Next, the motor and relay (if it has one — the KitchenAid under discussion uses a starting winding rather than a relay) must be checked out. Always assume that the motor is not the culprit in an appliance with a heavy duty motor, such as this one, but distrust everything up to the motor.
Among principal switches on a compactor are filter switch, key interlock switch, and start-stop program switch. In the Kitchen Aid model, the small fan motor (a 2-speed motor) is not in the main motor circuit. The electrical circuit goes from the three prong, grounded switch (ground is a green wire) to the interlock front switch via the black wire, to the key interlock switch, to the start-stop switch and the ram switch. The ram switch is wired with brown and orange leads off the start-stop switch. Next is the blue lead from the start- stop switch to the directional switch, then to the motor. The Perils of Pauline have nothing on the flow of electrical current to the motor. The motor’s start windings are black and red. The main winding lead is blue; a black lead that becomes brown feeds into the motor protection device, then goes to the opposite pole of the main winding, turning on the motor.
The interlock switches, and the ram switch, are simple, basically 2-lead affairs. The directional switch that controls motor operation has six positions. The start- stop switch has two leads for the ram switch and two for the key interlock and directional switches.
If you test switches for continuity, you have to sort out the leads. Some leads can be tested from nearby connectors that come apart. Others will require clips or prongs that penetrate the insulation. On trash compactors with relay switches instead of starting windings in the motor, the relay should be tested for continuity before anything else.