Isuzu 2000 Trooper Workshop Manual page 40

Chart "A" Blower Motor Dose Not Run
Step
1 Is relay (B-36) OK?
2 Is fuse C-19 (25A) OK?
3 Is resistor OK?
4 Is fan control knob OK?
5 Is blower motor OK?
6 1. Turn the ignition switch "ON".
2. Turn fan control knob "ON".
3. Check to see if battery voltage is present at chassis side
connector terminal No. B5-1
Is there a battery voltage?
Chart "B" Blower Motor Does Not Run At Low Position
Step
1 Is resistor OK?
2 Is fan control knob (Fan Switch) OK?
Chart "C" Blower Motor Dose Not Run At Medium Low Position
Step
1 Is resistor OK?
2 Is fan control knob (Fan Switch) OK?
Chart "D" Blower Motor Dose Not Run At Medium High Position
Step
1 Is resistor OK?
2 Is fan control knob (Fan Switch) OK?
HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–11
Action
Action
Action
Action
Yes
Go to Step 2
Go to Step 3
Go to Step 4
Replace control
Go to Step 5 lever assembly.
Go to Step 6
Poor ground or
open circuit either
between chassis
side connector
terminal No. B5-2
and No. B3-2 or Open circuit
No. I18-1 and between No.
body ground (No. C-19 (25A) fuse
B-2). and No. B5-1.
Yes
Go to Step 2
Open circuit
between chassis
side connector
terminal No. B3-1
Replace control
and No.I18-2.
lever assembly.
Yes
Go to Step 2
Open circuit
between the
chassis side
connector
terminal No. B3-4
Replace control
and No. I18-5. lever assembly.
Yes
Go to Step 2
Open circuit
between chassis
side connector
terminal No. B3-6
Replace control
and No. I18-3.
lever assembly.
No
Replace
Replace
Replace
Replace
No
Replace
No
Replace
No
Replace