Transmitters

Transmitter Diagrams:

Transmitter Components:

Locations of components

3 Earthing point, facia
At the left-hand front speaker socket

16 Instrument lighting rheostat
On the left-hand side of the facia

22A Fuse board
Behind the access panel in the glove compartment

59 Two-pole connector
Under the right-hand front speaker grille

197 Outdoor temperature transmitter (ACC)
On the fan housing, behind the bulkhead partition

216 Climate control unit
On the centre console, in the interior

217 Air mixture transmitter
Inserted into the air distribution housing in front of the servo-motor unit

218 Interior temperature transmitter
In the panel between the steering wheel and the centre console

219 Suction fan for the interior temperature transmitter
In the panel between the steering wheel and the centre console

223 Sun transmitter
Under the right-hand front speaker grille

230 Distribution terminal +30
In the electrical distribution box behind the glove compartment

231 Distribution terminal +54
In the electrical distribution box behind the glove compartment

Operation
The climate control unit receives information from the control panel and from the following transmitters.

Outdoor temperature transmitter 197, which senses the temperature of the air flowing into the ventilation fan. The transmitter is of transistor type and is connected across pins 16 and 25.

Mixing temperature transmitter 217, which senses the temperature immediately downstream of the air-mixing damper. The transmitter is connected across pins 4 and 25.

Interior temperature transmitter 218, which senses the temperature of the air in the interior. The transmitter is integrated into suction fan 219, which provides a uniform air flow around the transmitter. The transmitter is connected across pins 3 and 25.

Sun transmitter 223, which senses the intensity of sunlight. The transmitter, which consists of a photo-diode, is connected across pins 12 and 15.

The interior and mixing temperature transmitters are of thermistor type, the electrical resistance of which varies with the temperature.

Power supply
The supply to the climate control unit is taken across fuses 17 and 1.

The unit always receives a supply directly from the battery across fuse 17. This supply actuates the memory function, so that the setting made on the unit will be retained even after the ignition has been switched off.

When the ignition switch has been set to the drive position, the unit will also receive a supply across fuse 1. At the same time, suction fan 219 for interior temperature transmitter 218 will start.

Terminal 18 of the unit is connected to instrument lighting rheostat 16.

1988 model

NOTE:
The cooling fin of the speed control for the ventilation fan is live (+12V) when the ignition is switched on. The speed control will be irreparably damaged if the cooling fin is earthed.