A/C Clutch Circuit Test
Test
No.
Test
Test Procedure
Test Result
Action
5
Measure resistance
of the A/C clutch.
Disconnect the connector at the
A/C compressor. Measure
resistance on the compressor
side of the connector.
NOTE: If the vehicle is equipped
with a Denso compressor, the
thermal cutoff switch may have
failed causing an open in the
clutch circuit.
2.85–3.33 ohms
Problem is most likely high
resistance or open circuit in
wiring between the A/C clutch
relay in the PDM and the A/C
compressor. Be sure to check
A/C compressor clutch ground
circuit. The most definitive way
to isolate the problem is to
manually energize the circuit at
the relay and use voltage drop
measurements to isolate the
problem, then
go to test no. 6
.
Not 2.85–3.33 ohms
On Denso compressors,
disconnect the compressor
thermal cutoff switch and check
it for continuity. If the circuit is
open, replace the compressor.
Otherwise, replace A/C
compressor clutch, then
go to
test no. 6
.
6
Verify repair.
Verify that repair corrected the
fault code and the problem is
resolved.
Problem resolved
Done.
Problem unresolved
Repeat test no. 1
.
Table 4, A/C Clutch Circuit Test
Bunk Override Diagnosis
The front control unit will remember bunk override
setting after an ignition cycle and initiate bunk ove-
rride again. Both the front and auxiliary units will be
in bunk override mode.
See
for bunk override diagnosis procedures.
Heater and Air Conditioner Troubleshooting
83.00
Symptom Driven Diagnosis
122SD and Coronado Workshop Manual, Supplement 9, June 2014
350/11
