Convertible - Control Modifications
REF. NO. 77/35TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
DATE: April 1995
SUBJECT:
MODEL 129
A. POWER SOFT TOP CONTROL MODULE (N52) WITH SHORT-STROKE POWER WINDOW CONTROL
B. MODIFIED SEALS AND HOLDING RAILS ON POWER SOFT TOP AND HARDTOP
A. POWER SOFT TOP CONTROL MODULE (N52) WITH SHORT-STROKE POWER WINDOW CONTROL
As of December 1994, a modified power soft top control module (N52) has been phased into production. The new control module has the window lowering (short-stroke) feature as in model 140 coupe.
Modified parts:
Power soft top control module (N52), part number 129 820 32 26.
Left front power window motor with Hall sensor (M10/3), part number 129 820 75 42.
Right front power window motor with Hall sensor (M10/4), part number 129 820 76 42.
Additional new parts:
Left rotary tumbler switch (S87s2. Figure 1), part number 129 820 59 10.
Right rotary tumbler switch (S86s2, Figure 1),
part number 129 820 60 10 (1);
part number 129 821 26 51 (2)
(1) up to model year 1996
(2) As of model year 1996
DELETED PARTS
Left front door window down limit switch (S21/9).
Right front door window down limit switch (S21/8).
Operation of the power soft top:
The soft top switch (584) will light intermittently and the power soft top will stop in mid-travel during the opening sequence if the power soft top was operated prior to synchronizing the door windows after the battery was disconnected.
To complete the opening operation of the power soft top, first remove the key from the ignition switch. Then manually place the soft top back into the soft top storage compartment. Synchronize the door windows and then operate the power soft top again.
IMPORTANT
If the battery was disconnected or is discharged. do not open or close the doors when the windows are completely closed, as this may damage the window seals.
The battery must first be reconnected or fully charged before opening either front door. Additionally, the end position of the door windows is no longer stored in the power soft top control module (N52). As a result, the power soft top will not open fully.
IMPORTANT
The windows must be synchronized immediately after reconnecting the vehicle battery, so that the power soft top can be fully opened.
SYNCHRONIZING THE DOOR WINDOWS:
(1) Turn the ignition on (engine does not have to be started).
(2) Close all doors, press and hold the left/right front power window switches (521/1, S21/2) in the closing position until the door windows are in the fully closed position.
(3) Continue to hold the door window switches pressed for 5 seconds after door window movement has ceased.
(4) The end position of the door windows is now stored in the power soft top control module (N52).
INDICATION OF NON-SYNCHRONIZED POWER WINDOWS:
^ When opening the door, the window drops to approx. 20 cm. When the door is closed, the window does not close.
^ The power soft top does not complete its full opening or closing sequence; it stops mid-travel.
Note
With the ignition key removed, the soft top must be manually placed into the soft top storage compartment prior to synchronizing the power windows.
Diagnosis:
Please refer to Supplement 11 in the Diagnostic Manual, Body and Accessories, Volume 2, Section 11.3.
Wiring Diagrams:
Please refer to future wiring diagrams in a future supplement to the Electrical Troubleshooting Manual (ETM), Model 129, Volume 2.
B. MODIFIED SEALS AND HOLDING RAILS ON POWER SOFT TOP AND HARDTOP
Note
The modified seals and holding rails can not be installed on vehicles produced prior to the 12/94 production phase-in.
Power Soft Top
Hardtop
Figure 2 - Component Locations