I do not know if this could cause the problem or not but it is hooked up to an extension cord (not sure what size). There are two garage doors plugged in with extension cords. One is working but it is closer to the outlet. Could this be the cause of the problem? Either way I am going to install outlets so she can plug them in correctly.
99% of the time, the issue is the door sensor. Usually an infrared beam, it runs across the bottom of the doorway to reverse the door if anything blocks it. You'll need to check them. There's typically a green light unit (transmitter) and a red light unit (receiver). The red light will flash if there's no beam from the transmitter.
- Make sure they are aligned properly. If someone bumped it, it can fail easily
- Make sure the sun is not hitting the transmitter or receiver. In the spring and fall, it sometimes hits mine and causes issues at certain times of the day.
- Make sure nothing is covering any holes. My newer Genie unit has transmitters that have a nice hole for spiders to build a nest in. A can of compressed air can help with that
Running the extension cords is not causing the problem but you're smart to install the outlets and correct the installation.
The momentary operation of the wall switch triggers a normally open relay to close in the unit that operates the motor until the limit switches open the circuit. Check that relay.
Often the door opener, by not working, is working exactly how it is supposed to work because it's not supposed to work when there is a safety issue such as someone (a child) standing under the door.
If nothing is in the way of the door then the door opener is getting faulty information. The 'not supposed to work' signal comes from a safety sensor near the bottom of the door and near or on the metal door track.
It works by transmitting a type of light (we usually can't see it) across the door gap and seeing the reflection if it off of a reflector on the other side. If something blocks the light then it assumes that something is in the way, that the path is not clear.
For the door opener to get an 'ok the path is clear' the signal must be complete all the way around, from the door opener down a wire to the transmitter, across the door way, to the reflector, reflected back across the door way returning to the transmitter (also a receiver) and back up the wire to the door opener.
If any part of that path is incomplete then the door opener will not work. Usually it is simply a misalignment of the transmitter, it can't see the return signal not because something (or someone) is physically blocking it by being in the door way, but rather because it is not hitting the reflector and bouncing back. Less often the transmitter/ receiver is dirty, or broken, and sometimes the wire is cut or broken, or it is not attached properly.