Tool - A/C Compressor Thermal Fuse Tester
85jaguar01DATE . . . JANUARY, 1985
NUMBER . . . J85/04
MODEL: ALL
SUBJECT: COMPRESSOR THERMAL FUSE TESTER
KEYPOINTS: Thermal limiter fuse tester available from NAPA parts dealers. P/N 209921.
NAPA automotive parts dealers market a thermal limiter fuse tester, P/N 209921, which can be used to check the thermal fuse and super heat switch circuit. This inexpensive tester is recommended for all checks relating to the thermal fuse.
The following is an extract from the tester instruction sheet.
HOW TO USE TESTER
1) Remove thermal limiter from its connector and replace with thermal limiter circuit tester.
2) Start engine and turn on air conditioning system.
Bulb Replacements: GE No. 757 (LO) GE No. 1892 (HI)
TEST POSSIBLE CAUSES CORRECTION
TEST 1
LO light does - Blown fuse on test panel Repair or Replace
NOT light.
- Poor terminal contact
- Open circuit between temp control and thermal limiter and Ranco thermostat
If LO light ON - Condition "NORMAL" for
this part of test
TEST POSSIBLE CAUSES CORRECTION
TEST 2
PRESS BUTTON SWITCH Check refrigerant
ON TESTER pressure and proper
If compressor - Defective thermal limi- charge BEFORE re-
operates, ter placing thermal
limiter.
If compressor Poor terminal contact
does NOT operate,
- Open circuit between Repair or Replace
thermal limiter and compressor (poor grd)
- Defective compressor clutch
TEST 3
+If both HI & LO - Defective super heat Before replacing
lights ON switch and defective super heat switch
thermal limiter and thermal limiter,
pressure must be
-then- checked with engine
running & A/C sys-
TEST 4 tem on. Be sure
proper amount of
Place hold down refrigerant is in
over switch. Run system 2.5 +/- .25 lbs
system for minimum and expansion valve
of 10 minutes. is functioning pro-
perly. If system
reads normal, this
will confirm a super
heat switch failure.