Frequently Asked Questions

Bulletin 68-I-13 — Pontiac Motor Division Dealer Service Information Bulletin, Section 1A, dated October 31, 1967. Attention: Service Manager.

Subject: Revised Procedure for Evaporator Core Removal — 1967–1968 Pontiac, 1968 Tempest, 1967–1968 Firebird 6-Cyl.

Short answer: An improved removal method for the evaporator core or left case half is described below; the flat-rate times in this bulletin supersede those in the 1967 Flat Rate Manual and the new Warranty & Flat Rate Manual immediately.

Bulletin 68-I-36 — Pontiac Motor Division Dealer Service Information Bulletin, Section 1A, dated January 31, 1968. Attention: Service Manager.

Subject: Operating Instructions for 1968 Pontiac Custom Air Conditioning System.

Short answer: Owners and service personnel should understand the two rotary switches and six mode buttons of the 1968 Pontiac Custom A/C system; the Freon compressor operates automatically above freezing in any mode except VENT, and each button directs airflow differently.

There appears to be some lack of understanding as to proper operation of the new 1968 Pontiac Custom Air Conditioning system. Owners’ acceptance of this new and flexible system will be much greater if they are instructed as to its proper operation at the time of new car delivery or when cars are in for service.

The control panel should be used as follows: Set the two rotary switches on the left and right side of the control to the desired blower speed and air temperature, respectively. With the SYSTEM button in the OFF position, depress any one of the other five buttons (INSIDE, A/C, BI-LEVEL, HEATER, or DE-ICE). The system will now operate in the mode and at the temperature and blower speed selected. If ambient temperature is above freezing, the Freon compressor will also automatically operate to minimize potential fogging. If it is desired not to operate the Freon compressor, it can be shut off by merely depressing the SYSTEM button to the first detent stop, at which time VENT will appear in the left window. If any other button except SYSTEM is then depressed, the Freon compressor will again operate (temperature above freezing) until the SYSTEM button is once again depressed to VENT. An ambient switch prevents Freon compressor operation whenever the temperature is below freezing.

Air flow from the various outlets in the system is controlled by the mode buttons, in order of occurrence on the panel:

Bulletin 68-I-63 — Pontiac Motor Division Dealer Service Information Bulletin, Section 1A, dated May 9, 1968. Attention: Service Manager.

Subject: Parts Released for Servicing of 1968 Pontiac Standard A/C Control Panel.

Short answer: Two additional parts are now released for service on the 1968 Pontiac standard A/C control panel: the shaft, drive gear, and rack assembly, and the roller-control strings. Replacement procedures and flat-rate times are provided.

Master Switch — Replace

1. Remove control panel.
2. Remove one screw retaining switch bracket to control assembly.
3. Remove contact set from bracket.
4. To replace, reverse removal procedure.

Compressor Switch — Replace

1. Remove control panel.
2. Remove master switch and bracket assembly.
3. Remove two screws retaining compressor switch to assembly.
4. To replace, reverse removal procedure.

Rotary Vacuum Valve — Three Spigot — Replace

1. Remove control panel.
2. Remove pal nut.
3. Remove retaining clip (use new clip when replacing).
4. To replace, reverse removal procedure, being careful to place stud in cam slides.

Rotary Vacuum Valve — Nine Spigot — Replace

1. Remove control panel.
2. Remove two retaining clips.
3. Remove one retaining screw.
4. Remove valve.
5. To replace, reverse removal procedure.

Blower Switch — Replace

1. Turn switch to high.
2. Pull string off switch pivot and attach to string guide.
3. Remove switch and shaft assembly (two screws).
4. Transfer pulley to new switch shaft and set center of pulley track 2-7/8 inches from shaft end.
5. Install switch and attach string to pulley peg.
6. Rotate pulley on shaft until roller reads HI through window, then tighten set screw.
7. To replace, reverse removal procedure.

Blower Switch String — Replace

1. Remove control panel.
2. Remove three clips retaining lens and backing to panel.
3. Cut an eleven-inch length of string (1219143).
4. Securely tie string in a loop which, when taut, measures approximately 5-1/8 inches.
5. Feed string through eyelet behind roller.
6. With coil spring attached to temperature and motor speed indicator roller, rotate speed indicator roller once to load spring and slip string over stud on roller.
7. Reinstall lens and backing and check for proper operation (make sure lens is clean). At this point it may be necessary to adjust per step 5 above.
8. Replace panel by reversing removal procedure.

Temperature Switch String — Replace

1. Remove control panel.
2. Remove three clips retaining lens and backing to panel.
3. Cut a seven-inch length of string (1219143).
4. Securely tie string in a loop which, when taut, measures approximately 3-3/8 inches.
5. With coil spring attached to temperature and motor speed indicator roller, rotate temperature roller once to load spring and slip string over plastic stud on roller.
6. Reinstall lens and backing plate and check for proper operation (make sure lens is clean). Turn roller full clockwise; it should read all red. If necessary, bend wire that string attaches to for fine adjustment.
7. Replace panel by reversing removal procedure.

Shaft, Drive Gear, and Rack Assembly — Replace

1. Remove cold air duct, cable attaching screw, and disconnect cable.
2. Remove three screws retaining bracket to rear of control panel.
3. Remove knob and slip shaft out of guide.
4. Insert new assembly, making sure drive pin is in groove.

5. To replace, reverse removal procedure.

Flat Rate and Warranty Information

All times below include removal of the control panel (0.6 hour) except for the Shaft, Drive Gear, and Rack Assembly.

Bulletin 68-T-16 — Pontiac Motor Division Dealer Technical Bulletin, Section 1A, dated June 12, 1968. Attention: Service Manager.

Subject: Left Air Conditioning Duct Extension Loose — 1968 Tempest.

Short answer: On some 1968 Tempest air-conditioned cars the left duct extension may work loose and disengage. Installing two “S”-shaped clips corrects the condition. Flat-rate allowance is 0.2 hours straight time.

Bulletin 68-T-4 — Pontiac Motor Division Dealer Technical Bulletin, Section 1A, dated November 1, 1967. Attention: Service Manager.

Subject: 1968 Pontiac — A/C Blower Motors Hitting Case.

Short answer: If the A/C blower motor impeller contacts the evaporator case (typically at low blower speeds or during braking), install washer 3004686 between the motor and impeller to shift the impeller rearward. This also supersedes the blower motor removal procedure in the 1968 Service Manual.

Bulletin 68-T-4A — Pontiac Motor Division Dealer Technical Bulletin, Section 1A, dated February 28, 1968. Attention: Service Manager.

Subject: 1968 Pontiac — A/C Blower Motor Impeller Hitting Case.

Short answer: The A/C blower motor impeller-striking-case problem described in Dealer Technical Bulletin 68-T-4 has been corrected in production. The fix does not need to be performed on cars built after the Vehicle Identification numbers listed below.