XJ-S V12-5.3L (1982)
Control Module HVAC: Testing and Inspection
Amplifier
Amplifier
Amplifier
A/C Amplifier
Testing:
Select 85 at the temperature selector switch. This will cause the relay in the amplifier unit to switch purple lead of the motor circuit to 12
volts. Red lead should reflect 0 volts.
After a few minutes, select 65 at temperature selector switch. This will cause the other amplifier relay to reflect 12 volts at the red lead and 0
volts at the purple lead.
If camshaft does not rotate in either test, check wiring continuity, FULL HEATING and FULL COOLING limit switches for continuity.
If correct, check Diodes (D1, D2 and D3) for continuity in forward and reverse bias modes.
If Correct:
1. Check that there are 12 volts at the brown lead and ground potential at the black lead.
2. Select Def. - Amplifier relay should show 12 volts at purple lead.
3. Check fuse in brown supply lead, 4. Replace amplifier.
