A/C System - Modifications
REF. NO. 83/82TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
DATE: March 1995
SUBJECT:
ALL MODELS A/C SYSTEM MODIFICATIONS
This Service Information is divided into three sections.
A. MODEL 14O
1. Changes to the A/C vacuum system
2. Modified auxiliary fan preresistor (R15)
3. Outside temperature sensor (B10/5)
B. MODEL 202
1. Modified condenser
C. MODEL 129
1. Changes to the A/C vacuum system
A. MODEL 14O
1. Changes to the A/C vacuum system
As of 01/94 production (VIN A-182368), the main air flap is actuated by a vacuum element (44) with one vacuum line connection (Figure 1).
Vacuum element 43 was eliminated (Figure 2).
Note:
Only the modified version of the upper section of the heater box with one vacuum element (44) for the main air flap is stocked at the PDC.
When replacing the upper section of the heater box on vehicles produced prior to VIN 1A-182368, the dark red vacuum line is to be connected to vacuum element 44, and the previously used med. green/lt. blue vacuum line is to be plugged off. The switchover valve block (Y11) does not have to be replaced.
Diagnosis - Individual Flap Test
The individual flap test, display 10 and 11 is therefore revised.
The change to the Individual Flap Test ([ ] 13) also affects Preparation for Test ([ ]32) and Pneumatic Test ([ ] 33).
Parts Information
Vacuum diagram, vehicles as of A-182368
2. Modified auxiliary fan preresistor (R15)
As of 05/94 production (VIN A-206876), a modified auxiliary fan preresistor (R15) is installed (Figure 4). The function of the preresistor remains the same.
Note:
Vehicles as of VIN A-206876
The modified auxiliary fan preresistor with electric harness is available as a spare part. Cut vehicle's existing preresistor harness directly at the preresistor and install a 2-pole intermediate connector. Connect the new preresistor and harness to existing harness and route harness behind left headlamp. Secure excess harness and intermediate connector behind left headlamp to avoid water spray damage.
Vehicles up to VIN A-206875
The modified version preresistor can not be installed on earlier vehicles. Only the previous version preresistor can be installed.
3. Outside temperature sensor (B10/5)
The outside temperature sensor connector (B10/5X1) was deleted. The temperature sensor is now soldered directly to the harness (Figure 5).
Note:
Only the previous version outside temperature sensor with connector is stocked at the PDC. In case of replacement, the old temperature sensor is to be cut off the harness, and a connector soldered into place.
Parts Information
B. MODEL 202
1. Modified condenser
As of 08/94 production (VIN A-168525, F164270) an improved condenser is installed. The refrigerant fill quantity is now 850 g (see refrigerant label).
Note:
If the new version condenser is installed, the refrigerant label must also to be replaced and the correct fill quantity observed.
Parts Information
C. MODEL 129
1. Changes to the A/C vacuum system
As of 08/94 production (VIN A-107997), connection 3 on the switchover valve block (Y11) is no longer utilized. The vacuum element for the recirculated air flap (42) will be activated together with the left and right main air flaps (43 and 44).
Note:
Connection 3 on replacement valve blocks must plugged off.
Parts Information
Vacuum diagram, vehicles as of F-107997