Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 1398

ELECTRICAL-BODY AND CHASSIS  8-157

TEMPERATURE GAUGE AND THERMO

UNIT

Temperature Gauge On-Vehicle Inspection

1. Disconnect the temperature gauge wire connector.

2. Connect a 3.4 Watt test bulb 

1

 to the ground.

The  gauge  needle  should  move  the  middle  part  of  the

gauge

Temperature Gauge Off-Vehicle Inspection

Use a circuit tester to measure the temperature gauge
resistance.
Temperature Gauge Resistance

Ω

Standard

Measuring Point

With

Tachometer

Without

Tachometer

IGN (+) - Ground

130

-

IGN (+) - UNIT

82

-

UNIT - Ground

212

-

VOLTAGE

REGULATOR - UNIT

-

25

8-158  ELECTRICAL-BODY AND CHASSIS

Thermo Unit Inspection

The thermo unit is thermistor type and must be inspected
under the conditions as shown in the left chart.
1. Put  the  deviation  of  the  galvanometer  to  0  by  using  the

variable  resistor,  switch  the  thermo  unit  off  and  then

measure the resistance of the resistor through the bridge.

Confirm  that  the  resistance  is  continuously  variable  in  any

other points than those shown in the following table.

2. Dip the thermo unit into 80 - 90

°C (176 - 194°F) water and

confirm  that  there  is  no  bubble  continuously  coming  out  of

inside of the unit.

Replace  the  unit  when  the  result  of  inspection  is  found

abnormal.

Temperature

Check

condition

50

°C

(122

°F)

115

°C

(239

°F)

7V 55 

Ω

Gauge

Resistance

+33.6

226.0 

-36.6

+1.71

26.4 

-2.21

7V 25 

Ω

Gauge

value (

Ω)

-

+2.68

24.3 

-3.68

ELECTRICAL-BODY AND CHASSIS  8-159

FUEL GAUGE AND TANK UNIT

Fuel gauge On-Vehicle Inspection

1. Disconnect the fuel gauge wire connector.

2. Connect a 3.4 Watt test bulb 

1

 to the ground.

The  gauge  needle  should  more  the  middle  part  of  the

gauge.

Fuel Gauge Off-Vehicle Inspection

Use a circuit tester to measure the fuel gauge resistance.
Fuel Gauge Resistance

Ω

Standard

Measuring Point

With

Tachometer

Without

Tachometer

IGN (+) - Ground

223

110

IGN (+) - 7V

(0)

IGN (+) - UNIT

83

25

Ground - 7V

110

Ground - UNIT

140

135

7V - UNIT

25

8-160  ELECTRICAL-BODY AND CHASSIS

Fuel Tank Unit Inspection

Measure the fuel tank unit resistance between the connector
terminals 1 

F-1

 and 3 

F-1

 while shifting the float from “E”

to “F” point.

Fuel Tank Resistance

Level

Float position

mm

Standard resistance

Ω

F (B)

51.7

17 

± 2.1

1/2 (A)

49.4

45 

± 4.5

E (C)

166.9

120 

± 6.5