Electric Windows; Door Window Motor; Fault Analysis Procedure - Aston Martin DB7 Workshop Manual

Electrics
Electric Windows - Fault Analysis / Window Motor Removal
[n:m3^^
Electric Windows
Description
Power to the window wind circuits is available
when the ignition switch is on and is supplied
through a thermal cut-out to the left and right
window switches. The switches are double pole
plus earth so that the current through a window
motor may be switched in either direction to raise
or lower the window.
DB7 uses frameless door windows which seal
against rubber strips around the body shell door
opening. To avoid damaging these seals during
door opening, the door glass must be lowered
before the door can be opened. This function is
controlled by the window control units. The units
are mounted on the inside of each door frame and
will sense if a door handle is pulled to open the
door. Before releasing the door lock, the control
unit w i l l drive the window wind motor briefly to
lower the door window glass down until it clears
the window seals. Similarly, after closing a door,
the window motor will be run to raise the door glass
to seat the glass against the body seals.
Fault Analysis Procedure
a) If a window fails to operate, check for fuse failure
and the connectors for poor or open contacts.
b) Check the thermal cut-out by shorting across it and
operating either window. If the windows operate
with the short ci rcu it but not without, the cut-out is
faulty.
c) With the ignition on, battery voltage should be
available between the inputterminalsof the switches
and chassis. Operate each switch and ensure that
battery voltage is available between the switch
output terminals and chassis.
d) Measure voltagefrom each switch inputterminalto
the switch earth return terminal. If no voltage is
measured, the earth return line is open circuit.
e) Measure continuity through the wiring from the
switches to each motor. If continuity is correct,
remove the motor for bench testing.
6.7.04 Door Window Motor
Procedure
1. Remove the door trim panel and the glass inner
sealing trim.
Figure!. Window Securing Screws
2. Position the w i n d o w to gain access to the slider
bracket and glass securing screws.
3. Disconnect the battery earth lead.
4. Remove two screws securing the glass to each of
the two slider brackets. Loosen the two screws
securing the glass to the elevator rail.
6. Slide the elevator rail forwards until the glass
securing screws are opposite the wide opening of
the rail keyhole slots and remove the glass from the
top of the door.
7. Disconnect the window motor multiplug.
6-14
May 1996