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Starting pre-heater
Troubleshooting
An indicator lamp lights when the starting pre-heater is
engaged. Should it light during testing, the fault is in
the power supply circuit or in the operating circuit. But
first check the fuses and also relay 312.
If cable failure or short-circuit is suspected, carry out
the following checks:
1.
Engage the starting pre-heater and feel with the
hand the inside of the manifold where the retaining
bolts and cable connection are. Slight heat should
be felt after about 50 seconds.
2.
Measure the resistance through the heater coil be-
tween the stud where the cable is connected and
the outer retaining bolt at the other end. This resist-
ance should be approx. 0.3 ohm. High resistance
indicates failure. Low resistance points to short-
circuit, in which case the starting pre-heater fuse
has momentarily popped out when the starting pre-
heater engaged.
3.
Measure the power consumption with the current
gun aimed at the starting pre-heater cable. This
should be approx. 160 amperes at 24 volts.
No power consumption = cable failure.
High power consumption, or if starting pre-heater
fuse has popped out = short-circuit.
