Cooling fan operation

Cooling fan operation

The cooling fans are able to run at two speeds, slow (fans connected in series) or fast (fans connected in parallel).

Temperatures at which cooling fans operate: T-Series 2.0

Slow speed ...... On - 98C Fast speed ...... On - 114C L-Series (Bosch ECM) Slow speed ...... On - 105C, Off - 94C Fast speed ...... On - 112C, Off - 103C

The cooling fans will also operate on slow speed when the compressor clutch is engaged.

If the medium pressure switch located in the trinary switch housing reads a system pressure of 20 bar or above, the cooling fans will operate on high speed.

MEMS control unit (T-Series 2.0) Battery voltage is supplied from fuse 52 in the satellite fuse block on the N/K wire to one side of the coils on cooling fan relay 1, cooling fan relay 2 and the condenser fan relay located inside the relay module. The relay earth path is dependent on a variety of operating conditions.

Bosch ECM (L-Series) Battery voltage on the N/LG wire is supplied from fuse 19 in the engine compartment fuse box via the closed contacts of the main relay on the N/O wire to one side of the coils on cooling fan relay 1, cooling fan relay 2 and the condenser fan relay located inside the relay module. The relay earth path is dependent on a variety of operating conditions.