Rover ECM

Rover ECM

A feed is supplied from fuse 19 in the satellite fuse box on a LG/S wire to the cooling fan relay coil.

The fan relay output from the ECM provides an earth to energise the cooling fan relay on the S/U wire when the engine temperature reaches 104C. When the engine temperature falls below 94C the fan relay output from the ECM removes the earth to de-energise the cooling fan relay and deactivate the fan.

With the relay energised a feed can pass from fuse 4 in the engine compartment fuse box on the P/U wire via the relay contacts to the cooling fan motor on a U/P wire. Earth to the cooling fan is on a B wire.

Cooling fan operation - ’K’ Series Models

A feed is supplied from fuse 19 in the satellite fuse box on a LG/S wire to the cooling fan relay coil.

The fan relay output from the ECM provides an earth to energise the cooling fan relay when the engine temperature reaches 104C. When the engine temperature falls below 98C the fan relay output from the ECM removes the earth to de- energise the cooling fan relay and deactivate the fan.

With the relay energised a feed can pass from fuse 4 in the engine compartment fuse box through the relay to the cooling fan motor on a U/P wire. Earth to the cooling fan is on a B wire.

HORNS OPERATION

Battery power is fed to the horn relay in the multi-function unit (MFU), on a P/N wire, from fuse 3 in the engine compartment fusebox. Operation of either horn switch energises the horn relay by providing an earth on the B wire via the rotary coupler on the R and P/B wires to the other side of the relay coil.

When the horn relay is energised, battery voltage is switched fom fuse 3 on the P/N wire to the twin horns on P/Y wires. Earth for the horns is on B wires.

If the alarm is triggered, the alarm ECU earths the P/B wire feed to the horn relay coil, causing it to be energised and the horns to be sounded.