Diagnostic Procedure For A/C System

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: A/C system does not come on.

Fig 1: Identifying Front Air Control Circuit Diagram

CHECK POWER SUPPLY CIRCUITS FOR FRONT AIR CONTROL

Turn ignition switch OFF.
Disconnect front air control connector.
Turn ignition switch ON.

Check voltage between front air control harness connector M49 terminals 6 and 19, and ground.

TERMINALS AND IGNITION SWITCH POSITION REFERENCE

Terminals			Ignition switch position
(+)		(-)	OFF	ACC	ON
Front air control connector	Terminal No.	(-)	OFF	ACC	ON
M49	6	Ground	Approx. 0V	Approx. 0V	Battery voltage
M49	19	Ground	Battery voltage	Battery voltage	Battery voltage

Fig 2: Checking Voltage Between Front Air Control Connector M49 Terminals 6, 19 And Ground

OK or NG

OK: GO TO 2.

NG: Check 10A fuses [Nos. 8 and 19, located in the fuse block (J/B)]. Refer to FUSE BLOCK-JUNCTION BOX (J/B) .

If fuses are OK, check harness for open circuit. Repair or replace as necessary.
If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as necessary.

CHECK GROUND CIRCUIT FOR FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Check continuity between front air control harness connector M49 terminal 20 and ground.
  20 - Ground : Continuity should exist.
  
  Fig 3: Checking Continuity Between Front Air Control Connector M49 Terminal 20 And Ground
OK or NG

OK: Replace front air control. Refer to "FRONT AIR CONTROL ".

NG: Repair harness or connector.