Open Circuit Testing

Testing for an Open Circuit

Testing receptacle outlets or switches on your homes electrical circuit that has either quit working or is intermittent using analog digital multimeter or circuit tester.

How To Find Open Circuit in Mobile Home Receptacle Outlets

If your electrical outlet is not working, look at this information.  Mobile homes use a "one piece" style electrical outlet box that, if you open it up and look, compresses the wire together in a "v" shaped slot. These I find over time will break connection due to heating up from the current load being passed through them. I can usually troubleshoot this problem by merely tapping on the wall next to receptacle outlets or switches on the mobile home electrical circuit that has either quit working or is working intermittently and see if this causes the lights to blink. The scientific method is to determine in which direction a circuit is connected and using a volt meter find the last receptacle outlet that has power. A quick and easy way to find the outlet causing the problem is with a circuit tester. It can find open hot, neutrals and grounds (look at bottom of page). Multimeters can be complicated to use and understand.  Chances are that the open circuit problem is at this outlet the last one that has power, preventing the passing of electrical current to the rest of the circuit. These can be replaced with same type found at a mobile homes supply. However I prefer to remove the original type of device and install what is called a snap in box (also called an old work box) and then install either a receptacle outlet or switch of the standard home type to keep the problem from returning. I also feel this is the safest way to do it. Be sure to wrap the wire around the screws and not use the quick wire hole on the back of the device. Remember white wire (neutral) on the silver screw, black wire (hot) on the brass screw and ground wire on the green screw. In the mobile homes I have owned I replaced all the switches and receptacle outlets when I first got them. This repair can be done with less expense than you might think, if done by you provided you feel comfortable doing this yourself. Example of a single gang snap-in box, mobile home type outlet receptacle and switch insides are pictured below with a view of how the wires route through a mobile home style receptacle and switch, without the outer Romex insulation for easier viewing.

How To Find Open Circuit in Mobile Home Switch

Testing a switch is going to require taking the switch out of the wall and opening up the back after turning off the circuit breaker to that circuit. Once the back is off take a multimeter set for AC voltage in a setting range at or above 120 volts then test with the circuit live between the black wire (hot) and ground wire. Test again between the black wire (hot) and the white (neutral) wire. You do this on both sides of the switch with the switch in the ON position. If you have voltage on the input side from the breaker and no power on the output side to the light with the switch ON then that switch needs to be replaced. Look here for additional three way switch wiring and here for single pole switch wiring information. I recommend wearing gloves and safety glasses when testing a live circuit.

Snap In Old Work Electrical Junction Box

Snap In Old Work Electrical Junction Box Picture

Mobile Home Electrical Receptacle Outlet Wiring

Mobile Home Electrical Receptacle Outlet Wiring Picture

Mobile Home Electrical Switch Wiring

Mobile Home Electrical Switch Wiring Picture

Open Circuit Tester A must have circuit tester like the one pictured below is a real problem solver. I would not have been able to find problems as easily as I have without one. You can get them here they worth their weight in gold. Open Circuit Tester These types of circuit testers are by far the easiest to use. I like them better than digital or analog multimeter testers. One thing to note about them is that they will always show you correctly when a circuit that you are testing is OK, however sometimes they will tell you that you have an open ground , neutral, hot or crossed wiring in homes when that is not the case, but be assured that it is trying to tell you that there is a problem on that circuit if you have anything other than two yellow lights. These types of circuit testers have never failed me in finding a circuit problem or a problem with a receptacle outlet. If you plug this circuit tester in an outlet and it indicates a problem you need to check that outlet and possibly the receptacle outlet that is feeding to it. I have found many times that the outlet feeding to it was the problem.