Injector Cooling System

The following are installed to cool the injectors and feed lines:

• Injector cooling fan (V38)
• Injectoir cooling shroud
• Air hose
• Intake hose
• Thermoswitch F61 for V38
  • Tightening torque 15 Nm
  • Above 85°C shorts to earth
  • Below 79°C circuit opens
• Relay J97 for V38 is at position 15 in auxiliary relay plate

If the temperature rises above °85C in the injector area after the engine has been switched off the relay is connected to earth via the thermoswitch F61 and switches on the cooling fan. Having cooled off to below 79°C, the cooling fan is once again switched off. This procedure may be repeated a number of times. The injector cooling shroud should have a 25mm hole to direct some air against the underside of the bonnet to cool the injector lines - this is formed in later versions and should be cut if missing in older ones.

Checking operation of the injector cooling fan:

• Pull wire off thermoswitch F61 and connect to earth. Cooling fan should run
• If the fan does not run, check the operation of the relay for V38 (J97) as follows:
  • Pull connector off thermoswitch F61 and ground with a jumper lead
  • Pull relay from slot 15 in auxiliary relay panel
  • Connect diode test lamp between pins 4 and 6 of the relay socket
  • Diode lamp should light
  • If lamp does not light, locate and eliminate break in circuit
  • Connect diode test lamp between pins 2 and 6 of the relay socket
  • If lamp does not light, locate and eliminate break in circuit
  • Replace relay J97 for V38 in slot 15 of the auxiliary relay panel
  • Pull connector off injector cooling fan V38 and connect diode light to connector
  • If diode lights, replace V38
  • If diode does not light, locate and eliminate break in circuit

Checking operation of thermoswitch F61:

• Pull wire off thermoswitch F61
Connect ohmmeter between contact and thermoswitch housing
• Resistance to ground below 79°C - infinity
• Resistance to ground above 85°C - zero ohms