Windows - Open after Closing

91mercedes03

MB-NET ADMINISTRATIVE MESSAGE
NOVEMBER 06, 1991
MESSAGE # 435


SUBJECT: GROUP 72 - MODEL 140


IN CASES WHERE ONE OR MORE WINDOWS WILL NOT CLOSE PROPERLY (OPENS 2 OR 3 INCHES AFTER CLOSING), THE WINDOW SAFETY SYSTEM REQUIRES SYNCHRONIZATION. THE SYSTEM MUST BE SYNCHRONIZED AFTER DISCONNECTING POWER & BEFORE ANY TESTING. TO SYNCHRONIZE THE SYSTEM, SIMPLY CLOSE THE WINDOW WITH THE SWITCH (FIRST DETENT, NOT THE SECOND "AUTOMATIC" DETENT) AND HOLD THE SWITCH FOR AN ADDITIONAL 2 SECONDS AFTER THE WINDOW HAS FULLY CLOSED. THIS PROCEDURE IS ALSO OUTLINED IN SERVICE MICROFICHE AS JOB NO. 72-186.

IF THE PROBLEM PERSISTS AFTER SYNCHRONIZING, CHECK THE FOLLOWING:

1. CHECK WINDOW FOR EASE OF OPERATION, EXCESSIVE FRICTION, BINDING, ETC.

2. CHECK IF THE PROBLEM CHANGES WITH THE DOOR OPEN OR CLOSED. IF IT DOES, A MECHANICAL PROBLEM IS TO BE SUSPECTED.

3. CONVENIENCE CONTROL UNITS (N57) BEARING THE DATE CODE UP TO 2591 (WEEK 25 1991) MAY BE DEFECTIVE, AND SHOULD BE REPLACED.

4. CHECK THE WINDOW LIFTER SPEED SENSOR CIRCUIT (EXPLAINED BELOW).

PREPARATION: FUSES 35 (FRONT) AND 5, 6, 11 & 14 (REAR) ALL OK; DO NOT UNPLUG N57, BUT PROVIDE ACCESS. SYNCHRONIZE ALL WINDOWS.

CONNECT AN AC VOLTMETER AS PER THE TABLE BELOW. CLOSE THE WINDOW, & READ THE TEST VALUE WHILE OPENING THE WINDOW (HOLD THE SWITCH DOWN TO THE FIRST DETENT). REPEAT FOR "TEST 2".

NOMINAL VALUE FOR ALL TESTS IS 2 TO 3 VOLTS AC (WITH THE WINDOW IN MOTION), & THE WINDOW SHOULD OPEN. IF NOT, CHECK WIRING, OR REPLACE THE WINDOW LIFTER MOTOR, OR REPLACE N57 CONTROL UNIT.


THOSE OF YOU WITH AN OSCILLOSCOPE CAN LOOK FOR A SERIES OF SQUARE WAVE PULSES FROM THE SPEED SENSOR.

WINDOW CONNECTION, TEST 1 CONNECTION, TEST 2

F. LEFT N57 CONNECTOR A, N57 CONNECTOR A,
PINS 18 AND 13. PINS 18 AND 3.

F. RIGHT N57 CONNECTOR B, N57 CONNECTOR B,
PINS 18 AND 4. PINS 18 AND 9.

R. LEFT N57 CONNECTOR B, N57 CONNECTOR B,
PINS 5 AND 11. PINS 5 AND 13.

R. RIGHT N57 CONNECTOR A, N57 CONNECTOR A,
PINS 4 AND 2. PINS 4 AND 20.

FOR THE COMPLETE DIAGNOSTIC TEST, REFER TO THE DIAGNOSTIC MANUAL.