wrote:
It is a garage door opener, not a garage door. Just wanted to clear
this up. I got this from a friend who bought it years ago, but never
used it. He lost the manual. It was an old Genie.

A Yahoo search for "how to install a garage door opener" yielded this
as one of the first hits:

http://www.diynetwork.com/diy/diy_ki...984381,00.html

You need to measure the headroom, that is, the minimum distance between
the ceiling and the highest point of the door, which you find by
opening the door partially until its to reaches maximum height. The
opener may not work if the headroom is too small, but there may be a
special low-headroom adapter to get around this.

Assemble everything on the ground and cycle it a few times to make sure
the trolley travels correctly and doesn't get jammed at one of the
extremes. Most likely you'll have to set up the optical sensor and
transmitter to make the opener close. Use only a 3-wire *GROUNDED*
outlet for power, and realize that some 3-wire outlets aren't grounded
(this may be OK, but only if the outlet is protected by a ground fault
interupter). Remember the opener will be used in a wet environment, so
you must eliminate the possibility of electric shock.

Find the center of the garage door opening and install the bracket far
enough above this so the top of the door will never touch the bottom of
the rail. The opener attaches to this and is then swung up at the
opposite end. You'll need a ladder on which the opener can sit
temporarily before its attached securely to the ceiling with metal
brackets ("L" angle). These brackets may not be included with the
opener. You'll likely need to attach 2 L angles to the beams
overhead.with 1/4" lag screws, taking care to center the screws exactly
in the beams. Decide whether the L angles should go parallel or
perpendicular to the overhead wooden beams, and measure to center the
opener in the middle of the door opening. Drill holes of proper size
to prevent splitting the beams. Then to these L angles bolt flat
pieces of steel between the opener and L-angles, using 1/4" bolts,
nuts, and lock washers. Do NOT use metal pipe strapping for this; it's
far too weak. You probably want the kind of L angle and flat steel
that has a hole about every 1/2", resembling Erector Set beams. It's
important to use lock washers since the motor vibrates a great deal and
can cause bolts to vibrate gradually loosen. In addition, a jam nut
against each nut wouldn't hurt.

The trolley arm needs to be attached to the center of the door. Some
doors have a bracket for this, but with others you may have to install
a horizontal reinforcement beam.

Openers made in the past 10-15 years are designed to not close the door
unless the optical safety beam system is installed and working.
Install this device properly since it's one of the most effective
safety devices and by far the most sensitive one. You may need to
mount the brackets on blocks of wood to let them extend pas any door
springs that sit vertically near the floor. Use special electrical
staples with cardboard insulators to attach the wiring to the wall
since regular staples will pierce the wire insulation. Normally the
ends of the wires are stripped and simply wrapped around the contact
screws at the opener, but for a neater installation you can use
crimp-on spade connectors. Install the wiring for the wall button
similarly. Secure the wiring so it can't get tangled in the
mechanism, such as with nylon wire ties, and take care not to let it
abrade against sharp metal. To protect the wiring, either cover it
with split looming, or cover the sharp edges with the looming.

The first time you operate the opener, have the trolley disengaged, in
case it jams. After attaching it to the door, adjust the opening and
closing limits for the right amount of door travel. Finally, adjust
the force settings so the opener doesn't reverse during normal
operation. You may have to increase the force as the temperature
changes and affects the springs. If the door won't open or close even
with the greatest force settings, the door mechanism may be binding, or
the springs may have to be adjusted for proper balance. When a door is
correctly balanced it will slowly fall when opened about 1/3 of the way
and released, slowly rise when opened about 2/3 of the way and
released.