TROUBLE DIAGNOSES — Electrical Components Inspection (Cont'd) — A/C switch / Dual-pressure switch / Thermal protector
HA-84spec tableA/C switch table merges L.H.D. (A/C + DEF combinations) with R.H.D. (single A/C contact). Dual-pressure switch is the low-pressure cut-off + high-pressure cut-off combined unit; thermal protector is a normally-closed bimetal that opens on compressor over-temp.
Electrical Components Inspection (Cont'd)
A/C SWITCH
A/C switch — continuity check
- 1Check continuity between terminals at each switch position.
A/C switch — continuity per switch position
ON
L.H.D. — DEFON
R.H.D. — A/C—
Terminal (+)13
Terminal (−)12
ContinuityExists
ON
L.H.D. — DEFOFF
R.H.D. — A/CON
Terminal (+)13
Terminal (−)12
ContinuityExists
OFF
L.H.D. — DEFON
R.H.D. — A/C—
Terminal (+)13
Terminal (−)12
ContinuityExists
DUAL-PRESSURE SWITCH
Dual-pressure switch — operating thresholds
Decreasing to 177 – 216 (1.77 – 2.16, 1.8 – 2.2, 26 – 31)
Increasing to 2,452 – 2,844 (24.5 – 28.4, 25 – 29, 356 – 412)
OperationTurn OFF
ContinuityDoes not exist
Increasing to 177 – 235 (1.77 – 2.35, 1.8 – 2.4, 26 – 34)
Decreasing to 1,863 – 2,256 (18.6 – 22.6, 19 – 23, 270 – 327)
OperationTurn ON
ContinuityExists
THERMAL PROTECTOR
Thermal protector — operating temperatures
Increasing to approx. 135 – 145 (275 – 293)
OperationTurn OFF
Decreasing to approx. 120 – 130 (248 – 266)
OperationTurn ON