Honda Acura NSX 1991 Service Manual page 248

Idle Control System
-Troubleshooting
This signals the PGM-FI ECU when there is a demand for cooling from the air conditioning system.
Connect the ECU test harness
between the ECU and connector.
Disconnect "C" connector from
the engine wire harness only, not
the ECU (page 1 l-21).
Measure voltage between C3 (+I
terminal and A26 (-1 terminal.
A/C compressor clutch7
YES
Blower switch ON.
(To page 1 l-73)
Flowchart
Air Conditioning Signal
I
Substitute a known-
Connect the RED/BLU
t h e 4 P qonnector
clutch relay to body ground.
Is there a clicking noise from th
A/C compressor
Repair open in REDlBLU wire be-
A26 6)
terminal of
on the A/C
View from SUB RELAY
clutch?
YES
See Air conditioner in-
(section 22).