Power Window Fix

Crank windows are so last millennium. Electric windows, once considered an extravagance, are now routine even in cheapie econo-boxes. Who can be bothered to hand-crank a window down when we’re so busy with chow, java, chat, text, GPS, and iPod? Oh, yeah, and driving.

We love our power windows. So when you hit the switch and nothing happens, it’s time to tackle the problem. Don’t let the electricity intimidate you. The power window is a basic switched circuit just like a simple light bulb. Power comes from the fuse box to the switch. When the switch is pressed, it continues to the motor in the door, which raises or lowers the window.

Many things can cause an inoperable window — a broken wire, blown fuse, faulty switch, failed motor, bad connection, or stuck linkage. But most of the time, you’re looking at a failed motor. The fix is pretty straightforward.

We’re working on a ’93 GT convertible, which, like T-top cars, has thicker (i.e., heavier) glass than a coupe or hatchback. National Parts Depot supplied the motor and switches from its giant in-stock inventory. Latemodel Restoration supplied the surprisingly hard-to-find moisture barrier. And Orlando Mustang’s Tim Clingler supplied the manpower.

You’ll need only a few hand tools and a couple of hours to fix that dead window. Let’s get going.

All of our new parts were supplied by National Parts Depot. The company stays on top of new reproductions just hitting the market and offer high-quality parts, as well as lower-cost alternatives where practical. Left to right are the plastic pushpins for attaching the door panel, four-way master window switch, door lock switch, bezel with screws, and new lift motor with new mounting screws.

Remove the two Phillips screws from the bezel. Set the bezel aside (go easy; it’s plastic), and work the master switch out through the hole.

Start by testing the switch. If it’s OK, no more disassembly is needed. With the key on, use a 12-volt tester to track voltage through the switch. With the switch on, touch the probe to one of the switch’s posts. If it lights, 12V is present. The other pole should be cold, meaning no voltage. Pressing the button should allow current to flow across both terminals, lighting up the tester. A lighted tester means the switch is working right. Time to dig a little deeper.

A good switch means our problem is farther down the line, likely the electric motor. That means opening up the door. As we have for decades, we start by removing the armrest. Pry out the bolt covers. Remove the two 3/8-inch bolts in the center, and the two Phillips screws, one at either end.

At the door latch, pry out the bezel. Remove the bolt underneath. Pry out the plastic pushpins at the perimeter of the door panel. A specific tool is available for this. If you use the old screwdriver method, keep the blades as close together as possible so the pushpins don’t rip out the cardboard door panel.

Remove the speaker in the bottom of the door. This will be our access hole to the motor.

Now let’s check the motor. Disconnect the terminal in the door. It has two conductors.

With the ignition switch on, press the “window down” button, and use the 12-volt tester to check for voltage at the connection. If it lights, power is getting to the motor, indicating a good circuit and a bad motor.

These three 5/16-inch bolts hold the window motor in (arrows).

Remove the 7/16-inch bolt holding the window channel on the bottom of the door. The channel will probably need to slide away for clearance. The motor can now be removed from the door.

We’re pulling off the original water barrier to access the rest of the door’s innards, as we’re going change the door lock servo, too. But if you’re replacing only the power window motor and lubing the window channels, the water barrier can remain in place.

The driver’s window gets most of the use and commonly fails, as ours did. The original is on the right; NPD’s replacement on the left. Before installing, we ran the self-tapping bolts into the mounting holes to cut the threads and make installation easier.

Slide the new motor into place and bolt it in. Don’t forget to replace the bolt for the window guide on the bottom of the door.

We’re keeping all of the original connectors, so we cut the original terminal off the old motor and connected it to the connectors supplied with the new motor.

All window channels get a cleaning and a generous application of fresh lube — white lithium on the center guide, and spray silicone (spray it outside, not in the shop where it lingers and causes havoc with future paint jobs) on the window channels.

Latemodel Restoration has the Fox Mustang door water shields. A bit of 3M Strip Caulk (available at body-shop suppliers) holds it in place.

Our original switch still worked, but with everything apart, we took the opportunity to install a new one. NPD’s replacement switch is an exact replacement. We also replaced the door lock switch. Now it’s time for the test. The window now operates smoothly and quietly, in both directions. No more awkward moments opening the door at the bank drive-thru.

The door panel can now be replaced and the armrest reattached.

SOURCES

LATEMODEL RESTORATION SUPPLY
400 Jan Dr.
Hewitt, TX 76643
(866) 507-3786
www.latemodelrestoration.com

NATIONAL PARTS DEPOT
900 SW 38th Ave.
Ocala, FL 34474
(800) 874-7595
www.npdlink.com

ORLANDOMUSTANG
2475 Reed Ellis Rd.
Osteen, FL 32764
(407) 688-1966
www.orlandomustang.com