Troubleshooting - Yetter AIR ADJUST 2940 Operator's Manual

Problem
Tank pressure drops when compressor
shuts off
Compressor runs continuously & air
flow lower than normal
Excessive moisture in discharge
Compressor will not run
Excessive knocking or rattling
No air output from the RU, RD, and WT
ports even though pressure is
commanded and tank pressure reads
60psi or greater
No ECU/VDM present displays on Cab
Controller
The 2940-162 Dump Valve Harness is
not labeled on the 4) 2 pin pigtails
No tank pressure reading on cab
controller
Low or sporadic tank pressure reading
Air leaking out regulator knob
62
Troubleshooting Guide
Cause
1. check valve is leaking
2. loose pneumatic connections
3. water separator drain valve or
head pressure relief valve leak
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. excessive water in the air tank
2. high humidity
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. loose mounting bolts
2. worn bearing
3. cylinder or piston is worn
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. improper communication harness
connection between Cab Controller
and VDM
2. VDM failure
labels missing on the 2 pin cables
on the harness
pressure transducer failure
water separator/regulator assembly
plumbed incorrectly
Corrective Action
1. replace check valve
2. perform leak test & fix as needed (Page 44)
3. replace water separator drain valve or head
pressure relief valve
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
1.manually drain tank holding down the down arrow
on the cab controller
2. move compressor to low humidity area
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
1. tighten bolts
2. replace compressor
3. rebuild compressor
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
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
label as follows:
RM UP DUMP  Yellow/Black
RM DOWN DUMP  Orange/Black
AUX 3  White/Black
AUX 4  Purple/Black
1. replace pressure transducer
2. check pressure transducer connections
plumb water separator/regulator correctly
(air compressorwater separatorexit regulator
sideenter control box inlet port)