Modification notes
S83.70-0046-11
Stationary heater control unit summary
1 STH control unit
2 Blower actuation wiring strand
(black/red, black/violet and black wires)
3 Line rt/ws (red/white) (+ c. 30)
4 Circulation pump actuation wiring strand
(brown and black/white wires)
5 Timer wiring strand
(red, yellow and brown wires)
6 Heater adapter line
Attach cables and wiring strands to existing cables and wiring strands using cable straps when routing. Avoid chafing points, if necessary install chafe guard. Cut off or tie back excess wires and leads.
D83.70-1215-01
1 Route lines of stationary heater control unit:
Open cable duct (arrow) in left front wall.
Route wiring strand for fan actuation (2) with lines black red (sw/rt), black/violet (sw/vi) and black (sw) and the wiring strand for the timer (5) with the lines red (rt), yellow (ge) and brown (br) over the cable duct into the interior.
Lay heater adapter line (6) behind battery down to left side rail.
Route line red/white (rt/ws) (3) to positive terminal of battery.
Route wiring strand for circulation pump actuation (4) with the lines black/white (sw/ws) and brown (br) into the installation area of the electric circulation pump to the left firewall.
D83.70-1214-01
2 Determine the standard wiring strand (7) of the electric circulation pump in the area of the brake booster and strip back the insulation of the wiring strand.
3 Cut the line black/blue (sw/bl) of stripped wiring strand (7).
4 Cut the line black/white (sw/ws) (9) and brown (br) (8) of wiring strand for circulation pump actuation (4) to match cut line.
5 Connect the line black/white (sw/ws) (9) using a 1-pin connector (10) with the end of the line (11) of the cut line black/blue (sw/bl) leading to the circulation pump.
6 Insulate the end of the line (12) of the cut line black/blue (sw/bl) and line brown (br) leading away from the circulation pump and strap down.
D83.70-1146-01
7 Connect red/white (rt/ws) (3) line of stationary heater control unit to positive battery terminal via an auxiliary fuse holder (24).
8 Use 25 A fuse and connect cable with auxiliary fuse holder to existing cables near battery.
D83.70-1142-01
9 Lay blower actuation wiring strand (2) with black/red, black/violet and black wires under instrument panel to installation location of air conditioning pushbutton control panel.
10 Detach 5-pin plug (13) of removed A/C control and operating unit and unpin line yellow (ge) (14) from chamber 1 of plug.
Instead of the yellow line (14) a black/yellow (sw/ge) line may also be installed.
11 Attach plug connection to blower actuation wiring strand black (26) wire and insert cable into chamber 1 of connector in place of unpinned cable.
12 Connect blower actuation wiring strand black/violet (16) wire to unpinned yellow (14) wire using 1-pin connector (15).
13 Reconnect 5-pin connector to air conditioning pushbutton control unit.
D83.70-1143-01
14.1 Vehicles without anti-theft alarm system (ATA):
Strip blower actuation wiring strand (2) black/red (17) wire and tie back.
14.2 Vehicles with anti-theft alarm system (ATA):
Manufacture 0.5 mm2 extension cable for blower actuation wiring strand (2) black/red (17) wire from air conditioning control and operating module installation location to installation location of ATA control unit in driver's seat box.
Connect black/red (17) wire to extension cable (19) using a 1-pin connector (18) and route extension cable beneath instrument panel to driver's side wheelhouse.
Route extension cable downward via wheel arch and along circulation pump extension cable into driver's seat box.
D83.70-1188-01
Disconnect 21-pin connector from ATA control unit in seat box.
Attach receptacle to black/red (sw/rt) wire of 0.5 mm2 extension cable and insert extension cable into chamber 15 of 21-pin connector.
The illustration shows the line insertion side of the 21-pin connector.
Reconnect 21-pin connector to the ATA control unit.
D83.70-1145-01
15 Attach 4-pin connector (20) to timer wiring strand coming from control unit and plug housing (21) to timer (23) wiring strand (22):
Attach receptacles and plug connections to the wires.
Insert wires into connector and connector housing in accordance with timer connection pin assignments.
Timer connection pin assignments
Plug-in position Wire
1 rt (red) (+ c. 30)
2 ge (yellow) (timer/water heater control line)
3 br (brown) ()
4 bl (blue) (remote control, option)
The illustration shows the line insertion side of the plug and the plug housing. Plug-in position 4 remains free and is intended for connecting the remote control option.
16 Attach the connector to the plug housing and make connections to existing cables and wiring strands beneath instrument panel.
D83.70-1147-01
17 Cut off heater booster (25) standard connector and fit heater adapter line (6).
For better clarity the diagram shows the arrangement of the standard connector with the left-hand lamp unit removed.