Yetter AIR ADJUST 2940, Operator'S Manual

Page: 62 / 64

62
Troubleshooting Guide
Problem Cause Corrective Action
Tank pressure drops when compressor
shuts off 1. check valve is leaking
2. loose pneumatic connections
3. water separator drain valve or
head pressure relief valve leak 1. replace check valve
2. perform leak test & fix as needed
(Page 44)
3. replace water separator drain valve or head
pressure relief valve
Compressor runs continuously & air
flow lower than normal 1. excessive air usage
2. loose pneumatic connections
3. worn piston or inlet valve
4. clogged air filter element
5. pressure switch failure
6. defective safety valve
7. pressure On Valve leaking 1. decrease air usage
2. perform leak test & fix as needed
(Page 44)
3. replace/rebuild compressor
4. replace/clean air filter element
5. replace pressure switch
6. replace safety valve
7. deactivate the system, turn all pressures to 0psi,
reactivate the system
Excessive moisture in discharge 1. excessive water in the air tank
2. high humidity 1.manually drain tank holding down the down arrow
on the cab controller
2. move compressor to low humidity area
Compressor will not run 1. no power/breaker tripped
2. system deactivated
3. motor overheats
4. pressure switch failure
5. on/off solenoid failure
6. VDM failure
7. compressor failure 1. check power connections/breaker
2. press ENTER
– AIR ON displayed
3. let compressor cool, replace if needed
4. replace pressure switch
5. replace solenoid
6. replace VDM
7. replace compressor
Excessive knocking or rattling 1. loose mounting bolts
2. worn bearing
3. cylinder or piston is worn 1. tighten bolts
2. replace compressor
3. rebuild compressor
No air output from the RU, RD, and WT
ports even though pressure is
commanded and tank pressure reads
60psi or greater 1. no power/40A breaker tripped
2. system deactivated
3. J3 connector on VDM plugged in
upside down
4. improperly functioning PQE
5. communication harness
connection issue 1. check power connections/breaker
2. press ENTER
– AIR ON displayed
3.unplug J3 connector, check tab/slot sizes, reinstall
J3 connector properly
4. replace PQE
5. check all communication harness connections, be
sure all internal pins seated
No ECU/VDM present displays on Cab
Controller 1. improper communication harness
connection between Cab Controller
and VDM
2. VDM failure 1. start at the 6 pin connector on the back of the
Cab Controller and inspect all connectors and
connections to the VDM
2. Replace VDM
The 2940-162 Dump Valve Harness is
not labeled on the 4) 2 pin pigtails labels missing on the 2 pin cables
on the harness label as follows:
RM UP DUMP

Yellow/Black
RM DOWN DUMP

Orange/Black
AUX 3

White/Black
AUX 4

Purple/Black
No tank pressure reading on cab
controller pressure transducer failure 1. replace pressure transducer
2. check pressure transducer connections
Low or sporadic tank pressure reading
Air leaking out regulator knob water separator/regulator assembly
plumbed incorrectly plumb water separator/regulator correctly
(air compressor

water separator

exit regulator
side

enter control box inlet port)