There will be two on the chain one for the opening limit and another for the closing limit.
Sears garage door opener closes then opens again.
Erase all codes in your remote and then reprogram it.
These may be metal plates screwed on to the chain plastic snap ons dojiggies with flexible metal arms attached etc.
It is important to perform the safety reversing test after adjusting the force settings.
If this is a sears srt without external travel limit switches the internal travel limit is out of adjustment telling the opener to continue after the bottom of the door makes contact with the garage floor basically driving it into the ground until the force required exceeds what the safety system force is set at.
Else repeat the process once again.
Close the garage door with the opener and watch it closely as it closes.
The symptom of this is a garage door that is in constant motion opening fully then immediately descending only to start the same cycle again.
If the garage door does not close completely or begins to close and then opens back up again the down limit switch needs.
When your garage door opens or closes when you haven t triggered the remote one possible cause is that a neighbor s remote was programmed at the same time as yours.
If that doesn t fix the problem check the wiring between the motor unit and the wall control.
You have to keep adjusting till the garage door opens or closes fully without reversing.
If your garage door is closing fully and then reversing to open again then it may be due to a problem with the close limit switch.
Get logic board replacement.
As these wires short against the housing the electrical impulse causes the door opener to activate.
If the garage door fully opens or closes you are done.
There may also be loose wire connections inside the button housing itself.
Look for trip arms or clips attached to the opener chain.
When the logic board wears out it can cause your garage door to close then open and vice versa without explanation.
Hi in 2002 we purchased and had installed a craftsman 1 2 hp garage door opener model 139 53965srt.
Until a year or so ago we never had a problem with it.
In order to fix this you ll want to make small changes to the close limit setting until the door opener knows to stop once the door has reached the floor.
Operate your garage door opener.
