Diagnosing Cooling Problems - Norcold 3163 Service Manual

Read this information before attempting to perform
service on this refrigerator. Understand the service
procedures before performing the service.
WARNING
Always apply the safety precautions on page 1 and the
precautions listed below. Failure to follow these safety
precautions can result in substantial property damage,
severe personal injury, or death.
• Never bend, drop, drill, weld, or hammer the
cooling unit. Doing so can cause the cooling unit
to rupture, releasing chemicals under high pres-
sure. Contact with these chemicals may cause
severe burns to the eyes or skin.
• Never attempt to repair or recharge the cooling
unit. A defective cooling unit must be replaced.
Diagnostic Procedures
1. Make sure the cooling problem occurs while op-
erating the refrigerator in each mode of opera-
tion. If not, the cooling problem is not the cooling
unit. Refer to Trouble Shooting sections to deter-
mine cause for insufficient cooling on identified
mode of operation.
2. Make sure the interior venting is not obstructed
and is providing air circulation across the cooling
unit's absorber coils and condenser fins.
3. Make sure the 12 VDC ventilation fan is func-
tional. The fan will operate whenever the vehi-
cle's interior temperature reaches 85° or higher.

Diagnosing Cooling Problems

19
See pictorial and trouble shooting guide on
pages 17 & 18.
4. An off-level situation, if the infraction is marginal,
will allow the refrigerator to continue to operate
at a reduced level of cooling until the refrigerator
is leveled. Greater off-level situations will stop the
refrigerant circulation and cease cooling. Normal
vehicle leveling to provide comfort for the occu-
pants is within the refrigerator's operating limits.
The refrigerator's operating limits are 3 degrees
off-level front-to-back and 6 degrees off-level
side-to-side. Operating the refrigerator outside of
these operating limits for an extended time will
cause irreparable damage to the cooling unit.
5. Check the input voltages and gas pressure to
insure correct heat input and voltage limits.
The specifications are as follows:
a. 120 VAC - 108 VAC min. to 132 VAC max.
b. 12 VDC - 11.5 VDC min. to 15.4 VDC max.
c. Gas - 10.5" W.C. min. to 11" W.C.
Correct input voltages and propane gas supply
are critical for the cooling unit to function properly.
6. Check the area of the cooling unit for refrigerant
leaks. The smell of ammonia is a positive sign of
a refrigerant leak. When an ammonia smell is
detected, the cooling unit must be replaced. An-
other sign of a refrigerant leak is the appearance
of a yellow powder in the vicinity of the cooling
unit. When this powder is observed, the cooling
unit must be replaced.
7. Check the absorber coils; the bottom coil will be
warm and the top coil will be cooler. If the coils
are cold and the cooling units flue enclosure is
too hot to touch, there is a blockage in the cooling
unit and the cooling unit must be replaced.