Heater System Acura Integra III

DESCRIPTION

The heater system delivers fresh or recirculated air to the passenger compartment. Air passes through the heater unit and is warmed and distributed to selected passenger compartment outlets. The outlets are chosen by mode control buttons on heater control panel. The temperature control lever regulates temperature of delivered air. Blower motor is controlled by fan control lever.

Fan Control Lever

Sliding fan control lever to right increases fan (blower motor) speed, which increases air flow. (Scheme 1)

Fresh/Recirculated Air Button

This button controls the source of air entering the heater system. When Light Emitting Diode (LED) in this button is off, fresh air is brought in from outside vehicle. When LED is lit, interior air is being recirculated. Push button to change between fresh air and recirculated air modes.

When fresh/recirculated air button is pressed, a ground signal is sent from the heater control panel to the recirculation control motor. The motor then runs until the recirculation door reaches the opposite position. When recirculated air mode is selected, voltage is applied through dimming control circuit to the indicator, which comes on.

Mode Control Buttons

These buttons control the direction of air flow. The indicator shows which button is controlling air flow. When a mode is selected, voltage is applied through dimming control circuit to the LED, which comes on, indicating the mode selected. A ground signal is provided to the mode control motor through that mode switch. The motor then runs until the mode door reaches the proper position.

Temperature Control Lever

Sliding temperature control lever to right increases the temperature of air flowing out of the system.

Scheme 1

AIR MIX CABLE

Disconnect air mix cable from air mix control arm and clamp. (Scheme 2) Set temperature control lever to maximum heating. Move air mix control arm downward (away from cable clamp) and connect end of air mix cable to arm. Gently slide cable outer housing back enough to take up slack in cable, but not enough to move arm. Snap cable housing into clamp. Adjust heater valve cable. See HEATER VALVE CABLE.

HEATER VALVE CABLE

1. Disconnect heater valve cable from heater valve arm (in engine compartment) and from heater control arm and clamp (inside vehicle). (Scheme 2) Set temperature control lever to maximum heating.
2. Move heater control arm upward (away from cable clamp) and connect end of heater valve cable to arm. Gently slide cable outer housing back enough to take up slack in cable, but not enough to move arm. Snap cable housing into clamp.
3. Turn heater valve arm toward cable clamp and connect end of heater valve cable to arm. (Scheme 2) Gently slide cable outer housing back enough to take up slack in cable, but not enough to move arm. Snap cable housing into clamp.

Scheme 2

TROUBLE SHOOTING

BLOWER MOTOR DOES NOT RUN

1. Check fuse No. 37 (40-amp) in underhood fuse/relay block. If fuse is blown, replace fuse. If fuse is okay, go to next step.
2. Locate blower motor connector under right side of dash. Ground Blue/Black wire at blower motor connector. Turn ignition on. If blower motor runs, go to step 6). If blower motor does not run, go to next step.
3. Disconnect blower motor connector. Measure voltage between blower motor harness connector Blue/White wire terminal and chassis ground. If battery voltage exists, replace blower motor. If battery voltage does not exist, go to next step.
4. Turn ignition off. Remove blower motor relay from underhood fuse/relay block. Test relay. See «RELAYS»(/acura/integra/iii-1993-2001/remont/heater/#heater-system__relays) under TESTING. If relay is defective, replace blower motor relay. If relay is okay, go to next step.
5. Check for voltage at one of the blower motor relay sockets in underhood fuse/relay block. If battery voltage does not exist, replace defective underhood fuse/relay block. If battery voltage exists, go to step 9).
6. Ensure ignition switch is off. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Disconnect heater fan switch 6-pin connector from back of heater control panel. Turn ignition on.
7. Measure voltage between heater fan switch harness connector Blue/Black wire terminal and chassis ground. If battery voltage does not exist, repair open Blue/Black wire between blower motor and heater control panel. If battery voltage exists, go to next step.
8. Turn ignition off. Check for continuity between heater fan switch harness connector Black wire terminal and chassis ground. If continuity exists, replace heater fan switch. If continuity does not exist, check for open Black wire between chassis ground and heater control panel. If Black wire is okay, check for poor ground connections.
9. Turn ignition on. Check for voltage at Black/Yellow wire terminal of blower motor relay socket in underhood fuse/relay block. If battery voltage does not exist, repair open Black/Yellow wire between underhood fuse/relay block and underdash fuse/relay block. If battery voltage exists, go to next step.
10. Turn ignition off. Check for continuity between Black wire terminal of blower motor relay socket in underhood fuse/relay block and chassis ground. If continuity exists, repair open Blue/White wire between underhood fuse/relay block and blower motor. If continuity does not exist, check for open Black wire between chassis ground and underhood fuse/relay block. If Black wire is okay, check for poor ground connections.

BLOWER MOTOR RUNS, BUT ONE OR MORE SPEEDS ARE INOPERATIVE

1. Turn ignition on. Ensure fan control lever (heater fan switch) is in OFF position. If blower motor runs, go to step 6). If blower motor is off, go to next step.
2. Turn ignition off. Remove glove box. Unplug connector at blower motor resistor. Check resistance between blower motor resistor Blue wire and Blue/Black wire terminals. If resistance is 2-3 ohms, go to next step. If resistance is not 2-3 ohms, replace blower motor resistor.
3. Reconnect wiring to blower motor resistor. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Disconnect heater fan switch 6-pin connector from back of heater control panel. Turn ignition on.
4. Individually ground (in order listed) Blue wire, Blue/White wire, Blue/Yellow wire, and Blue/Black wire at heater fan switch harness connector terminals.
5. If blower motor runs at progressively higher speeds, replace heater fan switch. If blower motor does not operate as indicated, repair open wire(s) or check circuit(s) for high resistance between heater fan switch and blower motor resistor.
6. Ensure ignition switch is off. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Disconnect heater fan switch 6-pin connector from back of heater control panel. Remove glove box. Unplug connector at blower motor resistor.
7. Check for continuity between chassis ground and Blue wire, Blue/White wire, Blue/Yellow wire, and Blue/Black wire at heater fan switch harness connector terminals.
8. If continuity does not exist in all wires, replace heater fan switch. If continuity exists, repair short to ground in wire(s) between heater fan switch and blower motor resistor.

MODE CONTROL MOTOR DOES NOT RUN OR ONE OR MORE MODES ARE

INOPERATIVE

1. Remove driver's side lower instrument panel cover. Unplug mode control motor connector. Turn ignition on. Measure voltage between mode control motor harness connector Black/Yellow wire terminal and chassis ground. If battery voltage does not exist, repair open Black/Yellow wire between motor and underdash fuse/relay block. If battery voltage exists, go to next step.
2. Turn ignition off. Check for continuity between mode control motor harness connector Black wire terminal and chassis ground. If continuity exists, go to next step. If continuity does not exist, check for open Black wire between chassis ground and motor. If Black wire is okay, check for poor ground connections.
3. Test mode control motor. See «MODE CONTROL MOTOR»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under TESTING. If mode control motor does not test okay, go to next step. If mode control motor is okay, go to step 5).
4. Remove mode control motor. See «MODE CONTROL MOTOR»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Check mode control linkage and doors for free movement. If doors and linkage bind, repair linkage or doors as necessary. If doors and linkage move freely, replace mode control motor.
5. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Disconnect heater control panel 14-pin connector. Check for continuity between chassis ground and Yellow/Blue wire, Yellow wire, Blue/White wire, Green/Yellow wire, and Yellow/Red wire at mode control motor harness connector terminals.
6. If continuity exists, repair short to ground in wire(s) between mode control motor and heater control panel. If continuity does not exist in all wires, check the same wires for voltage. If voltage does not exist, go to step 8).
7. If voltage exists, repair short to power (battery voltage) in Black/Yellow wire between mode control motor and heater control panel. Also, replace heater control panel (short to battery voltage damages it).
8. Check for continuity of Yellow/Blue wire, Yellow wire, Blue/White wire, Green/Yellow wire, and Yellow/Red wire between mode control motor and heater control panel.
9. If continuity does not exist, repair open wire(s) between mode control motor and heater control panel. If continuity exists in all wires, replace heater control panel.

RECIRCULATION CONTROL DOOR DOES NOT CHANGE POSITION

1. Remove glove box. Unplug recirculation control motor connector. Turn ignition on. Measure voltage between motor harness connector Black/Yellow wire terminal and chassis ground. If battery voltage does not exist, repair open Black/Yellow wire between motor and underdash fuse/relay block. If battery voltage exists, go to next step.
2. Turn ignition off. Test recirculation control motor. See «RECIRCULATION CONTROL MOTOR»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under TESTING. If recirculation control motor does not test okay, go to next step. If recirculation control motor is okay, go to step 4).
3. Remove recirculation control motor. See RECIRCULATION CONTROL MOTOR under REMOVAL & INSTALLATION. Check recirculation control linkage and doors for free movement. If doors and linkage bind, repair linkage or doors as necessary. If doors and linkage move freely, replace recirculation control motor.
4. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. Disconnect heater control panel 14-pin connector. Check for continuity between chassis ground and Green/White wire and Green/Red wire at recirculation control motor harness connector terminals.
5. If continuity exists, repair shorted wire(s) between recirculation control motor and heater control panel. If continuity does not exist, check the same wires for voltage. If voltage does not exist, go to step 7).
6. If voltage exists, repair short to power (battery voltage) in Black/Yellow wire between recirculation control motor and heater control panel. Also, replace heater control panel (short to battery voltage damages it).
7. Check for continuity of Green/White wire and Green/Red wire between recirculation control motor and heater control panel. If continuity does not exist, repair open wire(s) between recirculation control motor and heater control panel. If continuity exists in both wires, replace heater control panel.

TESTING

Heater Fan Switch

1. Remove heater control panel. See «HEATER CONTROL PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION. With heater fan control lever (heater fan switch) in OFF position, no continuity should exist between terminals of 6-pin connector. (Scheme 3)
2. With fan control lever at 1, continuity should exist between terminals "A", "D" and "F". With fan control lever at 2, continuity should exist between terminals "A", "B" and "F".
3. With fan control lever at 3, continuity should exist between terminals "A", "E" and "F". With fan control lever at 4, continuity should exist between terminals "A", "C" and "F". If continuity is not as specified, replace heater fan switch.

Mode Control Switch

1. With heat mode button depressed, continuity should exist between terminals No. 1 and 4. With heat/defrost mode button depressed, continuity should exist between terminals No. 2 and 4. (Scheme 1)and (Scheme 3).
2. With defrost mode button depressed, continuity should exist between terminals No. 3 and 4. With vent mode button depressed, continuity should exist between terminals No. 4 and 7. With heat/vent mode button depressed, continuity should exist between terminals No. 4 and 8. If continuity is not as specified, replace heater control panel.

Recirculation Control Switch

With fresh/recirculated air button in fresh air position, continuity should exist between terminals No. 4 and 6. (Scheme 3) With button in recirculated air position, continuity should exist between terminals No. 4 and 5. If continuity is not as specified, replace heater control panel.

Scheme 3

MODE CONTROL MOTOR

1. Remove driver's side lower instrument panel cover. Unplug connector from mode control motor. Apply battery voltage to Black/Yellow wire terminal of motor connector and ground Black wire terminal of motor connector.
2. Individually ground (in order listed) Yellow/Green wire, Light Green/Black wire, Light Green/White wire, Blue/Red wire, and Blue wire at mode control motor connector terminals.
3. Each time each wire is grounded, the mode control motor should run smoothly and stop. If motor does not operate as indicated, remove motor. See «MODE CONTROL MOTOR»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION.
4. Check mode control linkage and doors for free movement. If doors and linkage bind, repair linkage or doors as necessary. If doors and linkage move freely, replace mode control motor.

Note. If motor does not run when Yellow/Green wire is first grounded, ground that terminal again after grounding the other terminals. The motor is okay if it runs when grounding Yellow/Green wire terminal the second time.

RELAYS

1. Remove relay. Ensure continuity exists between terminals "B" and "D". Ensure no continuity exists between terminals "A" and "C". If continuity is not as specified, replace relay. If continuity is as specified, go to next step.
2. Apply battery voltage across terminals "B" and "D". (Scheme 4) Ensure continuity exists between terminals "A" and "C". If continuity is not as specified, replace relay.

Scheme 4

RECIRCULATION CONTROL MOTOR

1. Remove glove box. Unplug connector from recirculation control motor. Apply battery voltage to Black/Yellow wire terminal of motor connector. Momentarily ground both Green/White wire and Green/Red wire terminals of motor connector.
2. Each time wires are grounded, the recirculation control motor should run smoothly and stop at fresh air or recirculated air position. If motor does not operate as indicated, remove motor. See «RECIRCULATION CONTROL MOTOR»(/acura/integra/iii-1993-2001/remont/heater/#heater-system) under REMOVAL & INSTALLATION.
3. Check recirculation control linkage and doors for free movement. If doors and linkage bind, repair linkage or doors as necessary. If doors and linkage move freely, replace recirculation control motor.

REMOVAL & INSTALLATION

Remove glove box and glove box frame. Unplug connector from blower motor. Remove 3 screws and blower motor. To install, reverse removal procedure.

Remove glove box and glove box frame. Unplug connector from blower motor resistor. (Scheme 5) Remove screws and resistor. To install, reverse removal procedure.

Scheme 5

1. Disconnect air mix control cable from heater case. Remove rear window defogger switch and hazard warning switch. Remove 2 screws and pull out heater control panel/center air vent assembly.
2. Unplug connectors from heater control panel. Remove 4 screws and separate heater control panel from center air vent. To install, reverse removal procedure. Adjust air mix cable and heater valve cable. See «AIR MIX CABLE»(/acura/integra/iii-1993-2001/remont/heater/#heater-system__air-mix-cable) and HEATER VALVE CABLE under ADJUSTMENTS.

Removal

1. Drain radiator coolant. Disconnect heater valve cable from heater valve arm. Disconnect heater hoses at firewall. Remove heater mounting nut on engine compartment side of firewall.
2. Remove instrument panel. See «INSTRUMENT PANEL»(/acura/integra/iii-1993-2001/remont/heater/#heater-system). Remove wire harness clips from heater duct. Remove 4 screws and heater duct. Remove bolts, nut, and passenger's side air bag support beam.
3. Disconnect wiring harness(es) from heater case. Remove heater case mounting nuts. Remove heater case from vehicle. Remove damper arm cover from heater case. (Scheme 6) Disconnect link from damper arm. Remove damper arm. Remove heater core cover. Remove heater core pipe clamp and heater core.

Installation

To install, reverse removal procedure. Apply sealant to heater case grommets. Loosen bleeder screw on water outlet (where upper radiator hose is connected to engine). Fill radiator and coolant reservoir until no bubbles come out of bleeder screw. Connect all cables and ensure they are properly adjusted. See AIR MIX CABLE and HEATER VALVE CABLE under ADJUSTMENTS.

Scheme 6

1. Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL SERVICING. Slide seats backward. Remove bolts from front of seat track. Slide seat forward. Remove seat track end covers and bolts. Disconnect driver's side seat belt switch connector. Remove front seats.
2. Pull up on parking brake lever. Remove access cover (below parking brake lever) and screws. Remove screws from sides of rear console. Lift front of rear console and slide it rearward to detach front hooks. Remove rear console.
3. Remove ashtray and cigarette lighter/front console panel assembly. On manual transaxle equipped vehicles, remove shift lever knob. On all models, remove shift lever trim/dust boot.
4. Remove screws from front and sides of front console. Tilt up front console from rear and turn it to clear parking brake lever. Remove front console. Remove driver's side lower instrument panel cover. Remove knee bolster.
5. Remove glove box. Remove clock and sun roof switch. Remove radio/cassette player. Remove bolts/nuts and lower steering column. Remove nuts and passenger's air bag bracket.
6. Disconnect air mix cable and connectors. Disconnect radio antenna lead. Unplug connectors from fuse/relay block. Remove covers and 2 bolts from sides of instrument panel. Remove 4 bolts from center and sides of instrument panel. Lift and remove instrument panel.

To install, reverse removal procedure. Ensure electrical harness and heater control cables are not pinched during installation.

Remove driver's side lower instrument panel cover. Unplug mode control motor connector and detach harness from heater case. Remove screws and mode control motor. To install, reverse removal procedure.

Remove glove box. Remove glove box frame (if necessary). Unplug recirculation control motor connector. (Scheme 5) Remove screws and recirculation control motor. To install, reverse removal procedure.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• HEATER VALVE CABLE
• RELAYS
• HEATER CONTROL PANEL
• AIR MIX CABLE