Fiat 1998 Marea Weekend, Service Manual

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Auxiliary units
Climate control
Marea-Marea Weekend
9 9 range
50.
The second piece of information is the electric power level available and this is obtained from the battery
voltage; if the voltage is higher than 12.8 V then the operation of the heater plugs is enabled and below
this value either one, two or all three of the heater plugs are gradually deactivated.
This parameter is checked every 10 seconds in order to always keep the power absorbed under control so
that the battery does not get run down.
The information concerning the engine speed is used to prevent the operation of the heater plugs when
the engine is not running, the enablement figure is about 660 rpm.
Either one, two or all three heater plugs are operated by two relays:
1st level activated by the first relay.
2nd level activated by the second relay.
3rd level activated by both relays.
There is a third relay/safety switch which interrupts the supply to the heater plugs if the earth contact is
not correct; the metal device containing the heater plugs is, in effect, connected to the engine earth via a
special cable loom, if this connection is interrupted, the relay stops the current supply to the heater plugs.
4 Print n° 506.763/17