Electrical Center - Modified and Polarity Change

86mercedes02
TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS

DATE: November 1986 REF..NO. 54/14,83/21


SUBJECT: MODIFIED ELECTRICAL CENTER MODEL 201.024 MODEL YEAR 1984

FIGURE 1 - MODIFIED ELECTRICAL CENTER:

FIGURE 2 - MODIFIED TEMPERATURE SWITCH:

Beginning with model year 1985, a modified electrical center (Figure 1) was phased in since the polarity of the switch for the electro-magnetic engine fan coupling was reversed from negative to positive. At the same time the 100°C temperature switch (S25/1, Figure 2) has been changed from a 1-pole to a 2- pole version.
Note: Only the modified electrical center is available as replacement. When installing the modified electrical center in subject vehicles, only the 2-pole 100°C temperature switch together with a supplemental wiring harness must be used.
Subsequent Installation of Supplemental Wiring Harness and 100°C Temperature Switch Model 201.024, Model Year 1984

1. Remove air filter housing.

FIGURE 3 - TEMPERATURE SWITCH:

2. Remove temperature switch (S25/1 Figure 3) and replace with 2-pole unit.

FIGURE 4 - SUPPLEMENTAL WIRING:

3. Remove 2-pole plug (left arrow) from connector (b) and reconnect it to temperature switch (S25/1).

4. Connect 2-pole plug of supplemental wiring harness to connector (b).

5. Connect 1-pole connector supplemental wiring harness to 1- pole plug of the previous ture switch.

6. Connect ground cable of supplemental wiring harness to ground (W11).

7. Attach supplemental wiring harness, using a tie strap (right arrow) to main harness.

8. Check operation of electromagnetic clutch of engine fan by turning on ignition and bridging the 2-pole plug of the temperature switch (S25/1). The electromagnetic clutch should engage.

9. Install air filter housing.

Parts Information
Part Name Part Number


Temperature switch (2-pole) 006 545 15 24
Supplemental wiring harness 201 540 43 10
Tie strap 002 997 09 90
Electrical center 201 540 04 50


S.I. MBNA 54/14,83/21
Time Allowance

02-5412/41 Supplemental wiring harness and 100°C temperature 0.5 hrs.
switch, subsequent installation (with electrical center replacement)