80 L5-2309cc 2.3L SOHC (NG) (1991)
A/C Signal: Testing and Inspection
CIS-E III Control Unit Harness Connectors (Pin # Locations)
The A/C control unit signals the fuel control unit when the air conditioning is turned on by applying battery voltage to terminal #33 of the fuel control
unit.
1.
Disconnect harness connector from fuel control unit.
2.
Turn ignition "ON", and check voltage between harness connector terminals #33 and #35 (ground). There should be no voltage present.
2.
Turn A/C on. Compressor clutch should energize and voltage at terminal #33 should change to battery voltage (within 1 volt). If not, check for
open or grounded circuit between fuel control unit terminal #33 and A/C control unit terminal 1/87a.