Function Tests; General; Repair Shop Level Testing - Webasto Dual Top ST 6 Workshop Manual

6

Function tests

6.1

General

This section describes the tests that you must conduct on the
heater when it is installed and not installed to verify that it is in
working order.
DANGER
Do not operate the heater in enclosed spaces (such as
garages) due to the risk of poisoning and asphyxiation.
6.2

Repair shop level testing

ATTENTION
For function tests always disconnect the connection
between the control unit and the component to be
tested.
Resistance measurement of eletrical heating elements
During the test the electrical heating elements (each Dual Top
ST 8 has 2 electrical heating elements) are to have the following
values:
Dual Top ST 8, resistance at 20 °C: 53 Ω
Test current: < 5 mA
Glow plug resistance test
NOTE
The resistance test must be carried out with an ohm-
meter suitable for small resistance values or Webasto
Thermo Test PC Diagnosis.
A resistance test with a simple digital multimeter is too
inaccurate to find the precise values. A new glow plug
can be measured to act as a reference.
The glow plug should have the following values in the test:
Glow plug: 12 V (red)
Resistance at 25 °C: 0.190 to 0.250 Ω V
Test current: < 5 mA
Air temperature resistance test
If you conduct this test with a digital multimeter, the air temper-
ature sensor (see Fig. 7) must have the values shown in the fol-
lowing diagram:
Fig. 5 Characteristic resistance values of a PT 2000 overheating sensor
within a temperature range of 10 °C to 30 °C.
Water temperature sensor resistance test
A: Resistance in kΩ
B: Temperature of water temperature sensor -G18- (see Fig. 7)
in °C
C: Resistance as a function of temperature
9019782C WSH Dual Top ST
Fig. 6 Characteristic resistance values of water temperature sensor
Table 501: Technical data water temperature sensor
Temperature Resistance
[°C] nominal
[Ohm]
-10 14,939.00
-5 11,425.00
0 8,816.00
5 6,855.00
10 5,373.00
15 4,241.00
20 3,372.00
25 2,700.00
30 2,175.00
35 1,763.00
40 1,438.00
45 1,180.00
50 972.80
55 806.30
60 671.80
65 562.40
70 473.00
75 400.00
80 339.70
85 289.50
90 247.80
Air temperature switch
The air temperature switch (see Fig. 7) opens at 145 ± 5 °C.
Water temperature switch
The water temperature switch (see Fig. 7) opens at 90 ± 5 °C.
Overheating protector
The overheating protector (temperature switch heat exchanger,
see Fig. 7) opens at 352 ± 15 °C and closes at 240 °C.
Fuel pump
Fuel pump test:
Pumping quantity 40 ml ± 10 % for operation at 7 Hz for 180
seconds.
Function tests | 6
Resistance Resistance
min. [Ohm] max. [Ohm]
14,351.00 15,528.00
10,991.00 11,859.00
8,493.00 9,138.00
6,613.00 7,097.00
5,190.00 5,556.00
4,102.00 4,379.00
3,266.00 3,479.00
2,619.00 2,781.00
2,107.00 2,244.00
1,706.00 1,821.00
1,390.00 1,487.00
1,139.00 1,220.00
938.10 1,008.00
776.80 835.80
646.60 697.00
540.80 584.00
454.50 491.60
383.90 416.00
325.80 353.60
277.50 301.60
237.30 258.30
17 / 39