A/C - Increased Defroster Performance
Classification:HA93-007
Section:
Air Conditioning
Reference:
TECHNICAL BULLETIN NTB93-059
Models:
1993 Altima
Date:
March 16, 1993
A/C COMPRESSOR OPERATION DURING DEFROST MODE
APPLIED MODEL:
1993 Altima, Manual Temperature control system with Air Conditioner.
APPLIED VIN:
Altimas produced before February 15 1993.
Vin # 1N4BU31FX*PC173007
SERVICE INFORMATION
Optimum Defroster operation occurs when the A/C compressor is engaged. On vehicles produced after the applied VIN number the A/C compressor is automatically engaged when the Defrost mode button is selected. For those customers of earlier vehicles who would like increased Defroster performance (quicker window clearing in humid conditions) the following modification will allow automatic A/C compressor operation in the Defrost position.
SERVICE PROCEDURE
1. Record the radio presets and disconnect the negative (ground) battery cable.
2. Using clean hands, remove the instrument cluster (with control head) utilizing the following procedure:
A. Lower the steering wheel, rotate the steering wheel so that it is at the normal (12:00) position, and cover the top of the steering column with a clean rag to protect the finish.
B. Remove the main cluster panel by removing and saving the 5 screws. A carefully pry the panel down and out on the driver (left side). As the cluster comes loose, carefully pull the panel free of all its clips.
C. Disconnect the mirror control harness, and cruise control harness (if equipped). As the driver end of the panel comes free, be careful not to scratch the top of the steering column.
D. Disconnect the following harness connectors from the back of the cluster panel in the center of the vehicle:
1) clock (black, 6 pin)
2) control head (white, 6 pin)
3) control head (brown, 6 pin)
4) control head (black, 16 pin)
5) control head (black, 12 pin)
6) control head (white, 3 pin)
7) hazard light (white, 8 pin)
3. Separate the Y/R wire from the harness at connector M 29 (black, 12 pin) and cut the wire approximately 2 inches from the connector.
4. Wrap the end of the cut wire (vehicle side) with insulating electrical tape.
5. Connect a 14-gauge jumper wire (approximately 4 inches long) with a Scotchlock(R) connector to the LG/R wire of the M30 connector (white, 3 pin).
6. Connect the jumper wire that you attached to the LG/R wire with a "Butt" connector to the Y/R wire, at the M29 connector (not the vehicle side).
7. Separate the Y/B wire from the M 28 connector (black, 16 pin) and cut the wire approximately 2 inches from the connector.
8. Wrap the end of the cut wire (vehicle side) with insulating electrical tape.
9. Connect a 14-gauge jumper wire (approximately 4 inches long) with a Scotchlock(R) connector to the LG wire of the M30 connector (white, 3 pin).
10. Connect the jumper wire that you attached to the LG wire with a "Butt" connector to the Y/B wire, at the M29 connector (not the vehicle side).
11. Reconnect the M28, M29, and M30 connectors to the control head.
12. Reconnect the negative (ground) battery cable and test the A/C system for proper operation. Check the system under the following conditions.
A. Fan speed 3 or 4
B. A/C button OFF
C. RECIRC ON
D. Mode FACE
E. Engine ON
Depress the DEFROST mode button. The A/C compressor should engage and the RECIRC function should turn off (go to fresh air). NOTE: this field fix allows for A/C compressor engagement for the DEFROST mode only. It does not engage the compressor for FOOT/DEFROST.
13. Re-connect the remaining connectors to the instrument cluster and re-install. Be sure not to pinch any wires during re-installation on the instrument cluster.
14. Re-program the radio presets and reset clock.
WARRANTY INFORMATION:
This is a running production change and retrofit of this modification is at the Customer's/Dealer's expense, as the pre-production change "Push Control Module" operates as designed, i.e., without a/c compressor operation in "defrost" mode.