Strange light switch problem.

An electrician I had hired started several upgrades in my daughter's home, but never returned to finish them.

I received help here on a previous portion of the mess he left behind - much appreciated.

The final problem is with a switched porch light.

A cable runs from a junction box in the basement to a switch on the wall, then continues through the wall to the outside fixture.

At the switch, the two live black wires are connected to the switch terminals. The grounds are grounded to the box. Neutrals are connected. At the fixture, the connections look fine.

BUT - the light does not work, and is apparently receiving current whether the switch is in the on or off position (checked with a simple beeping tester).

I've replaced the switch, thinking it was faulty, but still no progress.

The other circuit running from the same junction box to a switch, then light fixture works fine.

What is going on?

 

It is probably the tester you are using. Just check the fixture operation using the switch.

 

Which proves nothing. Sorry to say they don't work for this type of testing. False positives are common. You need a test light or multimeter, preferably analog. Check the connections at the source box, not by looking, but by taking them apart, examine the inside of each wire nut for corrosion or broken spring then reconnect. If there are any back stab connections move to the screws.

 

The fixture will not operate regardless of the switch position.

Tried a second tester - it also shows power at the fixture with switch in on or off position.

 

You could try a dozen non contact testers and they would be just as useless. You need a multimeter or test light or solenoid tester (Wiggy). Non contact testers don't work for this.

A $8-$15 analog multimeter is what you really need. Don't get a cheap digital because they can be fooled by induced voltage just like the non contact tester. Cables must be disconnected for best testing. Test from black to white and black to ground.

 

The switch should have power on one side and the switched hot on the other. Have you checked the junction box downstairs?

 

I'll not depend on those testers any more. Are they good for anything?

I checked the connections at the junction box. They are solid -connected with those brass connector/set screw/cover type connectors. Everything is tight.

 

Till you have a meter or tester to actually test voltages, you will continue to spin your wheels. You need to check the voltage, hot to neutral and hot to ground at the switch and then at the fixture with the switch turned on.