Question:
We have a residental Lift-Master Garage Door Opener. Recently, the light of
the right sensor did not turn on after a severe thunderstorm (the left one
was all right) and the door could not be lowered. I replaced both sensors
with new ones from Lift-Master, and the light of the right sensor still did
not turn on (the left one was all right). What might be the problem? Any
suggestions?
Answer:
You are looking for an "open" (break) in the wires. you need a
screwdriver to remove the wires from the terminals, and an ohmeter or
continuity tester to test for continuity in the wire.
Disconnect both ends of the wires, and twist the wires together at
one end. This forms a loop of wire open at one end. Use the tester to
check for continuity through the wire. If you get continuity through
the loop, untwist the wires and test again. If you still get
continuity, the wires are shorted: either way that wire will need to
be repaired or replaced. My experience in installing doors & openers
would suugest that the problem is probably caused either by a staple
through the wire, or the wire was installed "too tight" and has broken
at a corner or staple.
