garage door opener

edray

I have a craftsman garage door opener. I replaced gears and now door will only move about 6 inches then goes back. Opener has two threaded screws on side of open that I believe are limit switches and two screw on back of opener for p and down force. I have tried to adjust up down screws by doesn't seem the change anything. Thanks for any help.

Jackofall1

Hello and welcome Edray, to the best darn DIY'r site on the web.

If you can post a picture of the openner and a model number, this will assist us assist you.

Don't know if you have one of these but it may be helpful if you don't

http://download.sears.com/own/53992e.pdf

Mark

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shazapple

I had something similar happen after replacing the gears. If I remember correctly there was something wonky with the chain which was putting too much pressure on things. Did you try it without the door attached?

DexterII

Chain drive? Is it back in the exact position that it originally was?

edray

It is a Craftsman 1/2 hp. Model #139.53648srt2. It does the same thing with or without the door connected. Not sure if it is in same position that it was originally in. What do I do if it isn't?

firehawkmph

Ed,
When you say the door will only move about 6" then go back, is the door in the up position when it does this? If it is, it is acting like the eyes aren't aligned and seeing each other. Check the eyes and see if the small led lights are lit solid. When the eyes see each other, the lights will be solid, when they don't, one side will blink.
Mike Hawkins

DexterII

My dial-up is exceptionally slow this evening, for some reason, so I'm not sure, but think that number might be for the remote control. Anyway, where I was going was that maybe the trips for your limit switches are out of sync. Be careful that you don't get in the way of the door and knock yourself off of the ladder, but keep an eye on the limit swiches while you operate the door, and I think that you may find the problem there.

iamrfixit

Make sure the RPM sensor got reinstalled, it will definitely cause this exact condition.

It is a black segmented wheel that fits over the end of the motor shaft. It must be pushed on far enough that the wheel segments run between the sensors. Check the wiring also, it is easy to plug the wiring back in and miss one pin.

edray

It seems like it doesn't matter what position the door is in. Up or down or anywhere in between. I will check the rpm sensor. Thanks.

edray

checked rpm sensor. pushed it on tighter. works better. Now door goes up until limits switch stops it, but door will only go down about six inches then goes all the way back up. I have up screw all the way clockwise. and down screw about the same. Thanks

iamrfixit

Now that you have that fixed,

It sounds like you have the travel limit switches very far out of adjustment, neither of the limit screws should be completely clockwise. This is an easy fix but hard to explain how to do it.

With the trolley approximately at the mid position of the rail (door half open) the traveling portion (center) of the limit switch should also be about at the halfway point between the up limit and down limit contacts, similar to the picture.


As the opener raises the door; a small gear also drives the center portion of the limit switch until the metal contact touches the up limit contacts, turning the screw moves the point that this contact happens and allows you to fine tune the door position. The same thing happens when you close the door, the gear drives the center section to the other end until the contacts touch the down limit contacts, turning the down limit screw moves the contact point and allows you to fine tune the door closed position.

This switch has complete control of the door position, if the contacts do not meet, the opener will run until something physically stops it from moving. Such as the trolley hits the end of the rail.

Your force knobs control how hard the opener will push or pull until it reverses, these should be set as low as possible to make the door work. The higher these are set the more risk you have that the door or opener can be damaged. Be sure they are set to a lower adjustment and disconnect the door from the trolley until you get the limit switches in the correct position.

You can change the limit switch position by taking the switch off and turning the gear by hand. You can either try to run the opener to mid position or just take the chain off, move the trolley to mid position and reinstall the chain.

Be sure to disconnect the power while you are making changes inside the cover!

You may need to run the opener with the cover off in order to see and understand how all this works. It is not complicated, but it must be right or it will never work. The opener has to "know" what position the door is in at all times.

edray

I think I have limits switches in the right position. door stops at top and bottom. And raises fine, just wont go down more than six inches and then goes back up. I will thy to adjust up and down force screws. Thanks.

edray

I think that I might have the wires attached to the wrong contacts. does anyone have a schematic of the wiring for it. Or at least an idea of what goes where. My unit has three contacts numbered 1, 2 and 3. (Dah). 2 is in a white block and 3 is in a black block. Thanks

firehawkmph

#2white is like a neutral. Black is for the eyes. The wires on each eye should have one with a tracer or small lettering. Connect the tracer from each eye together at the opener and connect to the black #3 terminal. Other wire from each eye gets connected together and attached to the #2 white terminal. You should have a pair of wires from the wall station. The one with the tracer stripe goes to the #1 terminal, the other wire goes to the #2 white.
Mike Hawkins

bob22

See:
http://www.hammerwall.com/Manuals/Cr...ener/L9910253/
to download manual.
Picture: