Isuzu Trooper (2000 year). Service manual - part 11

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–13

Fan switch

position

Resistor terminals

with continuity

Resistance

1

1 — 2

2.4 

m

2

2 — 4

0.90 

m

3

2 — 6

0.28 

m

4

2 — 3

—

Fan Control Knob (Fan Switch)

1. Check for continuity between the terminals of the fan

switch.

865RS001

Fan switch

position

Switch connector terminals with con-

tinuity

OFF

No continuity

1

1 – 2 – 4

2

1 – 4 – 5

3

1 – 3 – 4

4

1 – 4 – 6

Heater & A/C Relay

1. Disconnect the heater and the A/C relay (B-36).

D

When removing the connector for relay, unfasten
the tang lock of the connector by using a
screwdriver, then pull the relay (1) out.

825RS001

2. Check for continuity between the heater and the A/C

relay (B-36) terminals.

825RS002

Condition

Relay terminals with

continuity

Normal

1 – 3 (Approx 85–105

m

)

When battery voltage is

applied between 1 – 3

2 – 4

1A–14 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Heater Unit

Heater Unit and Associated Parts

860RY00005

Legend

(1) Instrument Panel Assembly
(2) Instrument Panel Center Bracket
(3) Resistor
(4) Duct
(5) Evaporator Assembly (A/C only)
(6) Rear Heater Duct

(7) Heater Unit Assembly
(8) Center Ventilation Lower Duct
(9) Driver Lap Vent Nozzle

(10) Water Hose

(11) Electro Thermo Connector (With A/C)

(12) Resistor Connector

Removal

1. Disconnect the battery ground cable.
2. Drain the engine coolant.
3. Discharge and recover refrigerant (with air

conditioning)

D

Refer to Refrigerant Recovery in this section.

4. Remove the Instrument panel assembly.

D

Refer to Instrument Panel Assembly in Body and
Accessories section.

5. Disconnect the water hoses at the heater unit.
6. Disconnect resistor connector.
7. Remove duct.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–15

8. Remove evaporator assembly (A/C only).

D

Refer to Evaporator Assembly in this section.

9. Remove instrument panel center bracket.

D

Refer to Cross Beam Assembly in Body and
Accessories section.

10. Remove rear heater duct.

11. Remove heater unit assembly.

12. Remove driver lap vent nozzle.
13. Remove center ventilation lower duct.

Installation

To install, follow the removal steps in the reverse order,
noting the following points:

1. When handling the PCM and the control unit, be

careful not to make any improper connection of the
connectors.

2. Adjust the control lever assembly cables.

D

Refer to Control Lever Assembly in this section.

3. When installing the heater unit, defroster nozzle and

center vent duct, be sure that the proper seal is made,
without any gap between them.

1A–16 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Heater Core and / or Mode Door

Disassembled View

860RS001

Legend

(1) Case (Temperature Control)
(2) Mode Door
(3) Duct

(4) Heater Unit
(5) Case (Mode Control)
(6) Heater Core

Removal

1. Disconnect the battery ground cable.
2. Drain the engine coolant.
3. Discharge and recover refrigerant (with air

conditioning).

D

Refer to Refrigerant Recovery in this section.

4. Remove heater unit.

D

 Refer to Heater Unit in this section.

5. Remove duct.
6. Remove case (Mode control) and do not remove link

unit at this step.