One of the ways to connect a garbage disposal is with a dishwasher. The two must work together in order for the waste water to flow through the drain. It is also a good idea to have the garbage disposal in the line as it will catch the food particles that are still on the plates and pans when it is washed.
Many times when these two appliances are installed they are connected to the same wiring box. This is a good idea as the two are connected to the same circuit, but there are some problems in doing this. If one of the appliances is not connected the right way, neither of them will work. Upon installation it is important to go over everything to make sure it is right, but there are still may be problems as they are used. If you have a garbage disposal to dishwasher type of hook up here are some troubleshooting hints to help find and fix the problem.
One of the first steps is to check the circuit breaker. If it is not tripped then you should use a voltmeter to make sure there is power coming from the breaker. Also, check the connection of the wire that connects the breaker to the circuit. It may be loose. Tighten this connection.
Check Ground Wire
In many applications of the garbage disposal to dishwasher wiring connection there is a mix up of the ground wires. Both of the ground wires need to be secured to a grounding point. Check to make sure that this is so in your connection. It may be that the wire has come loose.
Circuit Breaker Not Compatible
Depending on whether or not you are using 14-2 or 12-2 wire you may have a problem with the actual amps of the circuit. If you are using a 12 gauge wire then it should be a 20 amp breaker. If the wire is 14 gauge than you should be using a 15 amp breaker. If the wires are mixed (meaning there is a combination of 14 and 12) you should be using the lower gauge amp.
Short in the Circuit
Many times, especially with appliances under the sink, there are times when the insulation around the wire is cut or rubbed away. When this happens the wire can touch other parts of metal or obstructions causing a short in the circuit. Check the wires for both the dishwasher and the garbage disposal.
Disposal Switch is Not Connected
Most garbage disposals need to be connected to a separate switch in order to turn them on and off. If you have just installed the garbage disposal, check to make sure the wiring is correct. If the wires are crossed neither the disposal or the dishwasher will work when connected to the same junction box.
Wires Are Secure
Loose wires are a serious problem with many appliances. When connecting the wires for the junction box, switch, or to the appliance themselves make sure that the wires are tight and secured with wire nuts. If not, they will work their way loose and cause problems with the operation.