Author Topic: Power Window Fix  (Read 1187 times)

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Offline TA78W72

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Power Window Fix
« on: January 29, 2015, 03:15:43 PM »
I started this thread for all the firebird owners who are experiencing problems with their windows.  While the purpose of this thread is to fix the power window problems, some of the fixes can be applied to crank windows.

The main problems associated with the windows are:
1.  Dirty window channels
2.  Bad window rollers
3.  Worn motors
4.  Loose rivets
5.  Loss of voltage

I'll go through each one in order.  The first and foremost thing you should do is address the dirty window channels and bad rollers.

1.  Dirty Window Channels.
In order to clean the window channels, the windows must be removed from the doors.  The grease used at the factory turned into a sticky, hard mess.  That's the biggest cause of the windows hanging up.  I think, over time, this caused stress on the electrical system and started burning wires and the switch.  At times, I could smell burning wire from my window circuit.

First, remove the window.  To protect the factory alignment, mark the bolts with a felt pen as shown:

Mark the bolts and remove the felt trim supports:

Mark and loosen the three window track bolts for both tracks:

Remove the nuts that hold the window to the sash.  The window has to be at three quarters down to reveal the nuts.

Keep your ratchet near.  Lift the window out of the tracks.  Mine caught right at the top on some debris that was in the channel.  I removed the three bolts from that track and it fell off the window roller.  My rollers were seized on the spindles and wouldn't swivel or roll as they should.

Remove the window and set it aside.  Remove the tracks.  Here's some pictures of my tracks before I cleaned them.

And, after I cleaned and greased them:

I also pulled the small channel for the regulator by removing these two bolts and sliding the channel off the roller:

Then slide the sash off the regulator.  It might hang up.  If it does, you'll need to clean the ends of the sash as debris can cause the rollers to hang up.

Once all the tracks are cleaned.  Clean the rollers on the regulator arms.  I used some brake cleaner and scrubbed them.

After everything is cleaned, lubricate the tracks with some lithium grease.  Also, grease the regulator rollers.

Side the tracks back on the regulator and fasten the small track with its bolts.

Install the window tracks but don't tighten the bolts.

2.  Window Rollers.
Classic sells a window hardware kit that contains everything you need to replace the window hardware.  You'll need this tool to replace the hardware:

Classic sells the tool.  I bought mine years ago off ebay.

It's a simple as removing the old hardware and installing the new stuff.  Here's a shot of my window with new hardware installed:

I greased the rollers before I installed the window.

Then install the window.  Once the window rollers engaged the tracks, I used one hand to lower the window and the other hand to get the studs into the sash.   Then tighten the window channel bolts per your marks.  Install the window up stops per your marks. 

Test the windows for performance.  If they still run slow,  You can either replace the motor or install the four relay system (or both).  Measure the voltage at the motor while the motor is running.  You should have close to 12 volts.  If you don't, you're a candidate for the four relay system.

3.  Worn Motors.
It's simple to replace the motors.  I can't post pictures because the motor is behind the inner door panel.  But you can get a wrench in there to remove the motor bolts.  There are three bolts.


Rebuilt motors are available for between $80-100.  They don't include the gears.  When I installed the motors, I pulled the gears out of the motor and installed it on the regulator.  Then I installed the motor over the gears and installed the bolts.  Take your time with the bolts, it's a tight space and access is limited.  I greased the gears before installing the motor.

4.  Loose Rivets.
This is a small item, but run the windows up and down and watch the rivets.  If they flex and move, they should be replaced.  You can either install another rivet or use 1/4-20 X1/2 bolts and nuts.  You can remove the old rivets by grinding them down and punching them out.

5.  Loss Of Voltage.
In 2006, I developed a wiring schematic for a four relay system to take the voltage off the power window switch.  There were a lot of complaints about slow windows and poor performance.  At the time, I didn't realize the root cause of the problem was the grease used by the factory.  Over time, as the grease turns into a sticky mess, the windows slow mechanically and stresses the electrical system.  Other problems in the electrical system also caused window slowing.  The breaker tends to reduce voltage, the relay reduces voltage, the switch reduces voltage and the wiring in general reduces voltage.  When I measured the voltage on my window system, under load, I lost voltage at each of these points.  My windows only had 7.3 volts at the motor.

Here's the schematic for the four relay system.  I originally drew this up on an excel spreadsheet which proved to be cumbersome.  Lee01 over at the gangsta site volunteered to use some better software to produce a better looking schematic.  That was back in 2006.  Here's the schematic:

There are two things I did differently from this schematic that I did differently.  First, there is no reason for a new ground from the window bolt to the cabin.  That circuit has plenty of ground without it.  Second, rather than bring in power directly from the battery or some other source, I tapped into the orange wire with the black stripe.  See the photo below:

The modified harness is shown on the left and the original harness is on the right.

You'll need four relay's.  I used Bosch 20/30 amp relays.  You can buy them here:

I used 12 gage wire.  The factory used 14 or smaller.  Here's a shot of both wires, factory and what I used:

You'll also need crimp on connectors, .250 both male and female types.  Also, some ring type connectors.

I ran new wires to the motors using the 12 gage wire.

1.  Disconnect the switch harness at the connectors behind the drivers kick panel.  One connector controls the driver side and the other carries power to the switch and drives the passenger side motor.  Here's a shot of those connectors:

Cut all the wires off the switch connector EXCEPT for the pink wire.  We'll use that to power the switch.

Unwrap the tape from that harness and reconnect the connector with the pink wire to it's counterpart connector.

Lay the relays out in front of the shifter and run the other four wires to the relay's.  The blue, light brown, dark brow and light blue with a white stripe will be used to trip the relays.  Cut the wires to the correct size and crimp on a female connector and connect the wires to the relay.  You've got to get the colors to the right terminals so the switch will deploy the correct function.  They connect to the number 86 terminal on the relay.

2.  Cut the connectors off the short harnesses that run to the motor.  Tape two wires to the end.  The original wires will be your "pull" wire to get the new wires through the boot.  Disconnect the white connector from the motor.  With the wires taped securely, slowing pull the new wires through the boot.  The new wires should be about 25 inches in length, you can trim them once they're through the boot.  With the new wires in place, crimp on some female connectors and connect the wires to the motor in the correct position.  (I used four different color wires to keep the up/down, right side/left side in order).  Trim the wires inside the cabin to the length you want them to be and install a male connector on the ends.

I wrapped my wires with electrical tape before running them through the boot. 

After installation:

I also connected the wires to the door like the factory did.  Just unclip the wire keep with a screw driver and pull the old wire out.  Lay the new wire in the keep and lock it by compressing the ends.

3.  Now measure out how much wire you need to run from the relay's to the wires that you ran through the boots.  I ran the drivers side exactly like the factory did.  I ran the passenger side towards the front of the car and then to the passenger side door.  This eliminated at least three feet of wire length for the passenger side. 

I wrapped the two drivers side wire with the pink wire, with electrical tape to make my own little harness.  I also wrapped the passenger side with electrical tape.  Install female connectors at the relay and connect them to terminal 30.  Make sure you get the up/down functions for each side correctly wired.

4.  Measure how much wire you need to run power to the relays.  Cut the wire and crimp a connector to the fusebox side and connect it to the harness you made.  Connect the other side to a loop connector.

Cut four, four inch lengths of wire and crimp a female connector to one end and a loop connector to the other.  Connect the female connector to terminal 87 of the relay.  Connect all five loop ends with a nut and bolt.  Wrap the ends with plenty of electrical tape.  Power will be always on at this connection.

5.  Cut four lengths of wire for the relay grounds.  Crimp a female connector to one end of the wires and a loop connector to the other.  Connect the female end to terminal 85.  Now cut a length of wire to connect to the ground on the drivers side of the floor pan.  There is a ground already connected there.

Secure all the looped ends of the ground wires with a nut and bolt.

You're done!  Connect the battery and check the windows making sure the switch is operating the correct function.  On this set up, you have to have the key in the on position for the windows to operate.

By the way, I replaced the breaker in the fuse panel with a 30 amp fuse.

If you need to replace one or more of the regulator rollers they are still available from GM.
The small roller that goes on the cam arm is part number 9666748 and simply presses on the end of the rod.

The larger rollers that roll in the sash are part number 03069189.  These come pressed on a new rod.  I'm not sure what tool you need to install these, but you could press them off the rod and press them on the regulator.

I don't believe new power window regulators are available.  I couldn't find a source.
« Last Edit: February 04, 2015, 11:54:23 AM by TA78W72 »