Nilfisk-Advance SW8000 Service Manual page 164

Service Manual – SW8000
Symptom: The Blower Motors run but there is no cold air coming out of the Evaporator-Heater Unit.
Note: Before troubleshooting the air conditioning system, make sure the system is filled with
the recommended amount of refrigerant. We recommend that you have this checked by a
qualified technician or an EPA-certified air conditioning repair shop.
Note: Refer to the Cab Electrical Wiring and Ladder Diagrams in Appendix, and the Component
Troubleshooting subsections on the following pages.
Check the cartridge on
Hydraulic Valve L10 and
clean/replace as necessary.
Check/replace A/C
Switch S35.
Check/replace
Thermostat S33.
The A/C system is
overheated. Check the
Condenser Fan Relay K9,
Condenser Fan and associated
wiring and replace/repair as
necessary.
Check the function of the
Compressor Relay K10 and
wiring and repair/replace as
necessary.
Check the auxiliary pump,
compressor motor and related
hydraulics.
There is no cold air from
the Evaporator-Heater
Unit.
Is there 12V across the coil on
the Compressor Hydraulic Valve
Yes
L10 (hopper down, A/C
switched on)?
No
Is there 12V at the WHT wire on
No
A/C Switch S35 (ref. to bat. neg.
w/A/C Switch S35 on)?
Yes
Is there 12V at the GRN wire on
No
the Thermostat S33 (ref. to bat.
neg.)?
Yes
Is there 12V at the GRN/WHT
No
wire on the Pressure Switch S34
(ref. to bat. neg.)?
Yes
Is there 12V at the BLU/BRN
wire on the Compressor Relay
No
K10 (ref. to bat. neg. with the
Hopper down)?
Yes
Is the hydraulic pressure at the
No
auxiliary pump test port within
specs?
Options and Accessories
Check the compressor and air
Yes
conditioning system components.
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