Functional Description

Functional Description

The fan P2 provides the necessary ventilation of the air for cooling the engine radiator and the conditioning system condenser.

This fan is always supplied by battery voltage through the line protected by the specific wander fuse G254, located next to the branch terminal strip: it is therefore operated by an earth control signal: this signal arrives directly (2nd speed) or via the additional resistance O22 (1st speed), fitted with a safety thermal contact.

Two relays I99 and I100, which receive the key-operated supply, the former (line of fuse F14 for fusebox "C") and the latter from relay I105 (supply controlled by the inertial switch H20), are energised by thermal contact L33 or by pressure switch Q20.

The fan is operated at the two different speeds by the two- level thermal switch L33 which controls the temperature of the coolant in the engine radiator: when a first level is reached, relay I99, in fusebox G1 is energised, which sends the earth control signal to the fan P2 via resistance O22: 1st speed.

If the second temperature level is reached, relay I100 on the fan duct is energised, which sends the earth control signal directly to the fan P2: 2nd speed.

Similarly, the pressure switch Q20 sends a signal from pin 3 for the 1st speed and from pin 6 for the 2nd speed.