How can I determine what is causing these electrical problems?

Question

My kitchen lights are having electrical issues that I am trying to identify probable causes for. When I bought the house, there was an overhead light in the kitchen and several plug-in light fixtures over the sink and stove, all working fine. The overhead light has two switches, one of which is a dimmer. The overhead fixtures are just on a wall socket, and have their own power switches on the devices.

I recently removed the overhead light and replaced it with a fan & light combination. It has both the light and the fan connected on a single regular 110V circuit, both to the same live & neutral connections. For about a week after the installation, the new fixture was working just fine. After about a week, the fan would continue to work, but the lights would not come on. I discovered that if I leave the lights set to "on", but repeatedly toggle the fan's directional switch (if left in the middle, the fan is "off"), the lights will eventually come on and will work simultaneously with the fan. Sometimes the lights will come on while the fan is not moving (switch for fan in the middle) and will go off again when the fan's direction switches. Turning off the fan altogether does not seem to coax the lights into working by itself. If the dimmer on the light is accidentally turned almost slightly, the lights will go out again, and the process has to be repeated after turning the dimmer back up. The fan itself continues to operate just fine no matter what we seem to do.

Shortly after moving in, the overhead plug-in light fixtures I mentioned earlier stopped working altogether. Replacing the bulbs in them seemed to have no effect. They are unfortunately installed behind the cabinets and I have been unable to reasonably test the lights on other circuits. I might just have to unplug them and cut the wall plug off just to remove them.

The two problems combined make me wonder if the circuit might just be overloaded and trying to draw too much power; otherwise I would just presume that the fan is defective.

I don't have the experience to diagnose what is going on, so when I found a DIY stack exchange forum, I decided to ask the question here. What does this situation sound like to you guys? I don't currently have a diagram of what the circuit looks like.

Answer 1

The problem with the light in the new fan/light combo is almost certainly an intermittent connection in the fan unit.

Often these units come with two sets of wires (one for light and one for fan) that you join together at the fixture for operation from a single switch. Your first point of investigation will be to lower the fixture and check that the wire(s) attachments are done properly and securely with good quality wire nuts.

There is also the less likely chance that the intermittent light connection could be in the light part of the fixture itself. This will require careful inspection of all the wiring up to the light socket itself. For some models of fixtures this may require some minor disassembly of the fixture.

Answer 2

Two years later, I decided to fix this completely. There were 5 cables; source, 3 for a 3-way switch, and one more for remaining circuit.

Whatever the previous homeowner had done was sloppy and dangerous; wires were haphazardly spliced such that a neutral was the fixture's load and another was its return, with three neutrals wired to the hot; it looked like the wiring got reversed and was spliced however just to fix it for an overhead light.

Unwiring everything and testing with a volt meter and voltage detector, turning the circuit on and off for testing and temporary splicing did the trick and everything is now wired correctly, black as load and white as neutral return.