MAINTENANCE
Gentherm Global Power Technologi
es
Page 58
Figure 27 - Electrode Protrusion from Air Box Lid
9.4.2
Check the Pressure Switch
Follow these steps to check the pressure switch:
1.
Remove the two wires from the pressure switch and connect a multi-meter across the
pressure switch terminals, set to measure resistance (ohms). One lead attached to
one terminal and the second lead attached to the other.
2.
If there is no fuel pressure in the system, check the resistance measured across the
switch is near infinity, which indicates the switch is open.
3.
Provide fuel pressure to the switch by opening the manual gas valve and holding open
the safety SO valve.
4.
Check the resistance measured across the switch is near zero, which indicates the
switch being closed. Replace the pressure switch if necessary.
NOTE:
Switch should close at pressures above 13.8 kPa (2 psig).
5.
Remove fuel pressure from the switch by closing the manual gas valve and use a wire
to join the two removed pressure switch wires together. This will cause the system to
attempt a start which will release the trapped fuel.
6.
If the TEG Controller is installed, after joining the two pressure switch wires together,
press the Start (S1) button to attempt a start to release the trapped fuel.
7.
Check the resistance measured across the switch is near infinity, which indicates the
switch being opened. Replace the pressure switch if necessary.
NOTE:
Switch should open at pressures below 6.9 kPa (1 psig).
8.
The SI controller must recognize that there is fuel available by the closed pressure
switch condition before it will power the SI module.
