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Craig
Craig, Electrical Technician
Category: Appliance
Satisfied Customers: 4529
Experience:  33 years experience electrical troubleshooting industrial equipment and control systems.
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Craftsman Garage Door opener sensor light is out. Does this

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Craftsman Garage Door opener sensor light is out. Does this indicate a bad sensor? Door will not close unless I hold down the wall control button. Can't do it with remote. If I just press and release, I get the flashing unit lights. Have checked wiring, alignment, everything the manual suggests in troubleshooting. By-the-way, how do I know if it's the sending sensor or the receiving sensor?

Craig :

This means the sensors are not aligned and need to be adjusted. Slowly move one side very slightly and watch for the light to come on.

Craig :

Don't get to crazy with the adjustment it's probably just a slight amount of movement will do it

Craig :

Watch for the LED light to come on. If it doesn't come on carefully check the wires all the way from the sensor to the controller for a staple pinching it or stuck through it.

JACUSTOMER-ydp1qjhm- :

I've done it. Played with it for over an hour. Even took it off the bracket, cleaned the lenses, and made sure the wires weren't shorted on any staples. The light in the sensor would never come on fully like the other.

JACUSTOMER-ydp1qjhm- :

LOL

Craig :

Look at above post

Craig :

Have you checked for a staple in the wire?

Craig :

Check the connections in the wire nuts

Craig :

Pull on the wires

Craig :

Check at the controller too

Craig :

check the screws on the wires

JACUSTOMER-ydp1qjhm- :

Above post? I traveled the entire length of the wires and checked the connection on the motor unit.. No wire nuts on this.

Craig :

none at the sensor?

Craig :

What about the terminals where the wires leave the controller

Craig :

Did you check the screws?

Craig :

The sensor usually has two wire nuts to connect it

Craig :

wiggle the wires, they can break at the terminals or wire nuts

JACUSTOMER-ydp1qjhm- :

No, none. Bell wire runs as a solid strand the whole distance. No splices or anything. Checked right at the controller. Even unscrewed the connection, check my wires and tightened down again. I suspect wire is broken inside the rubber grommet on the plastic housing. Not a complete break, just enough to fowl up the sensor and mess up operation

Craig :

Is the light on at all, dim?

JACUSTOMER-ydp1qjhm- :

It will come on dimly for just a second. I then go to the wall switch to open and close as a test. Opens of course but then the problem repeats when I try to close. Go back to the sensor and the light is out.

Craig :

Is there a red blinking light on the controller? How many times does it blink in a row?

JACUSTOMER-ydp1qjhm- :

Where would the red blinking light be. On the same side as the SRT button? I haven't seen one.

Craig :

On the back of the controller

Craig :

there is a fault code, one, two, three blinks all tell a fault

JACUSTOMER-ydp1qjhm- :

Let me go look. Will it be on now with the door closed?

JACUSTOMER-ydp1qjhm- :

Will it be under the motor housing cover?

Craig :

Not sure, try to open and see if you get a red blinking light. It will be in plain sight

Craig :

on the back

Craig :

near the learn button

JACUSTOMER-ydp1qjhm- :

Yea, red blinking lights are funny that way. Very obvious. :-) Just a sec.

Craig :

ok

JACUSTOMER-ydp1qjhm- :

Only light is the green on flashing near the SRT button. Is there a reset button anywhere?

Craig :

no

JACUSTOMER-ydp1qjhm- :

K. I've got a big baseball bat, will that fix it?

Craig :

the green is flashing?

JACUSTOMER-ydp1qjhm- :

Yes, flashing.

Craig :

Go to the manual and see what the light blinking is, how many blinks then a pause then more blinks?

Craig :

This usually means a fault of some kind

JACUSTOMER-ydp1qjhm- :

Looks like a constant intermittent blinking.

JACUSTOMER-ydp1qjhm- :

Its called the indicator light. Used to signify when codes are "learned." Looking for anything else.

Craig :

Has it always blinked like this?

Craig :

Do you recall?

JACUSTOMER-ydp1qjhm- :

I seemed to remember it doing it. I changed vehicles recently (3 months ago) and it was doing that when I went to change codes. Not seeing anything else.

Craig :

Go up near the motor and there is a 'RPM sensor' make sure it's plugged in tight

JACUSTOMER-ydp1qjhm- :

Where would that be?

JACUSTOMER-ydp1qjhm- :

Found the diagram.

JACUSTOMER-ydp1qjhm- :

I had that unplugged a few months ago when I changed the drive/worm gear. Give me a few minutes.

Craig :

ok

Craig :

give things a good clode look

Craig :

close look

JACUSTOMER-ydp1qjhm- :

Got in there and all seems properly connected. Unplugged the drive unit and then plugged back. Went to the sensor and did the wiggle adjustment to see if it would light. Nothing.

JACUSTOMER-ydp1qjhm- :

Hello?

JACUSTOMER-ydp1qjhm- :

I think I'm gonna have to bite the bullet and buy new sensors.

Craig :

It's a good possibility...

Craig :

Is there any way you could get one sensor over to the other for a close aligment?

JACUSTOMER-ydp1qjhm- :

How cheap can I be. I bought the thing 15 years ago. The worm drive was the first thing to go and that happened in October..

JACUSTOMER-ydp1qjhm- :

I thought of that but used a laser pointer to make sure they were lined up. The darn little green light on just one side will not go on.

JACUSTOMER-ydp1qjhm- :

Already there. $39.49. Anything else?

Craig :

could be a bad sensor

Craig :

no

Craig :

hope that gets you going

JACUSTOMER-ydp1qjhm- :

k, thanks. You confirmed what all my steps. Good thing is Sears Parts is a block from the office. Of course, if it snows here in San Antonio tonight the whole city will be paralyzed.

Craig :

Very cold here, 5 degrees now

Craig :

-10 this morning!

Craig :

Please press accept for my assistance. Thanks, Craig

Craig and 3 other Appliance Specialists are ready to help you
Customer: replied 6 years ago.
Confirmed sensor was the problem. Replaced it today and opener if fully functional.
Nice job! Thanks for the tip too. Craig