Vmac VR150 - VMAC Troubleshooting: Compressor Not Running; VMAC Troubleshooting: Frequent Over-temperature Shutdowns

VMAC – Vehicle Mounted Air Compressors
Toll Free: 1-800-738-8622 Local: 1-250-740-3200
Fax: 1-250-740-3201
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Always ensure that manual transmissions are in neutral
or automatic transmissions are in park with the park
brake applied before starting the engine or operating
the system
SYMPTOM
POSSIBLE CAUSE
CORRECTIVE ACTION
Compressor does
not run
Oil temperature too
high.
Turn compressor off, allow to
cool for 30 minutes, retry.
Oil level is too low.
Park on level ground, check level
at sight glass, add as necessary.
Drive belt is broken.
Install new compressor belt.
Check alignment of pulleys.
Replace automatic tensioner.
No power to the clutch.
Check for 12 V at the clutch,
check fuse, check for broken
wires or failed switch.
Bad clutch ground.
With 12 V applied to the clutch
check for voltage between the
clutch stator housing and the
engine. If voltage is present,
ground the stator.
Open clutch stator
windings.
With compressor switch off and
clutch wire disconnected, check
resistance between the input wire
and ground. Resistance (less
lead resistance) should be 2.5
ohms to 3.0 ohms. If outside this
range replace the stator.
Frequent over-
temperature
shutdowns.
Low oil level.
Check oil on level ground, add as
required.
Restriction in the
compressor oil hoses.
Check for kinked or pinched oil
hoses.
Compressor oil filter
plugged.
Replace oil filter.
Heat exchanger not
functioning or is fouled
with deposits.
Remove and clean or replace
heat exchanger.
Engine cooling system
failure (high engine
temperature).
Correct engine cooling problems.
Engine fan clutch
slipping.
Replace fan clutch.
High ambient
temperatures.
Reduce duty cycle.
Oil temperature probe
failure.
Replace if defective.
System needs service
Perform recommended service