A/C - Loss of Airflow from A/C Outlets After Highway Use
BULLETIN NO.: 98-T-10AISSUE DATE: September, 1998
GROUP/SEQ. NO.: HVAC-03
CORPORATION NO.: 781204R
SUBJECT:
Loss of Airflow from A/C Outlets after Extended Periods of Highway Driving (Adjust A/C Compressor Set Point.)
This bulletin is being revised to add the 1999 model year and supercedes Bulletin 98-T-10 which should be discarded.
MODELS AFFECTED:
1994-1999 Saturns equipped with R-134a air conditioning.
CONDITION:
After extended periods of highway driving, some customers may notice a loss of airflow from the A/C outlets.
CAUSE:
A/C compressor suction set point may be low for some customers usage and driving patterns, resulting in evaporator freeze after extended periods of highway driving.
CORRECTION:
Adjust A/C compressor set point using the following procedure.
NOTICE:
This procedure should never be repeated on the same A/C compressor. If condition is not corrected by this bulletin, refer to the diagnostic flow chart in the appropriate year "HVAC Service Manual."
PROCEDURES
1. Confirm with customer that A/C system functions normally in all conditions except extended driving at highway speeds.
^ If A/C system does not function normally at any other condition, refer to the A/C system diagnostic flow chart in the appropriate year "HVAC Service Manual."
^ If A/C system functions normally during all other conditions, proceed to the next step.
IMPORTANT:
Engine does not need to be running for the A/C compressor set point adjustment.
2. Locate the set screw on the rear head of the A/C compressor. The set screw will be covered with either a solid silver label or a silver label with the words:
CAUTION:
BE CAREFUL TO KEEP HANDS CLEAR OF THE ENGINE COOLING FAN. THE ENGINE COOLING FAN MAY OPERATE UNEXPECTEDLY.
NOTICE:
If the silver label has been broken, or an orange replacement label is present, DO NOT continue with this procedure. Additional adjustment of the set screw could result in reduced A/C system performance at higher ambient temperatures.
3. Determine where the large slot in the set screw is located. (The slot can be felt through the label with a screwdriver.)
a. Using a utility knife, cut through the label for access to the slot screw (1).
b. Using a permanent ink marker, make a mark on the A/C compressor to indicate the current position of the set screw in relation to the compressor rear head (2).
CAUTION:
DO NOT TURN THE SET SCREW ON THE BACK OF THE A/C COMPRESSOR COUNTERCLOCKWISE. THE A/C SYSTEM IS UNDER PRESSURE AND TURNING THE SET SCREW COUNTERCLOCKWISE COULD CAUSE THE SET SCREW AND/OR HOT REFRIGERANT/OIL MIXTURE TO BE DISCHARGED UNDER PRESSURE. THE REFRIGERANT/OIL MIXTURE CAN CAUSE BURNS AND/OR BODILY INJURY
NOTICE:
Do not turn the set screw more than 1/4 turn clockwise. Adjusting the set point changes the pressure at which the A/C compressor goes to minimum displacement. Increasing the adjustment beyond 1/4 turn clockwise will not make the system colder and could reduce A/C system performance at higher ambient temperatures.
4. Using a large blade screwdriver, turn the set screw 1/4 turn clockwise as viewed from the rear of the compressor.
5. Using a clean shop towel, wipe the surface area where the silver label is located. Make certain there is no debris or oil present.
NOTICE:
To prevent the A/C compressor set screw from being adjusted again, the orange A/C refrigerant caution label (P/N 21031284) must be installed over the old silver label.
6. Install a new orange A/C refrigerant caution label (P/N 21031284) over the old silver label that was cut in step 3a.
7. Start the engine and check that the A/C system is functioning normally.
PARTS REQUIREMENTS:
21031284 Label-A/C Refrig Caution.
CLAIM INFORMATION:
To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as shown.