Webasto Air Top 3500 Workshop Manual page 24

Air Top 3500/5000
6 Functional Checkouts
6.1 General
This section describes the tests on the heater in installed
and removed condition to prove its serviceability.
WARNING
The heater must not be operated in enclosed areas like
garages or workshops not provided with exhaust
ventilation facilities.
6.2 Adjustments
6.2.1 Adjustment of CO
6.2.1.1 General
The CO contents in the exhaust is adjusted by means
2
of the rotary setscrew of the control element.
The heater is preset by the manufacturer as applicable
for the combustion and heating air fan installed. The
manufacturer's setting may be corrected by changing the
control element adjustment (CO
ground). For adjustment a suitable CO
used.
6.2.1.2 Procedure
1. Connect CO pin (brown cable) in two pin connector
2
of secondary line at wiring harness end of heater to
vehicle ground using suitable adapter cable.
2. Switch heater on.
3. Adjust rotary setscrew on control element to centre
position.
Perform CO setting only 2 minutes after flashing of the
2
operating indicator light (stabilization time of CO
4. Wait until operating indicator light (LED) flashes.
5. Rotating the setscrew clockwise increases the fan
speed and decreases the CO
Rotating the setscrew counterclockwise decreases
the fan speed and increases the CO
Contents
2
pin connected to vehicle
2
detector must be
2
NOTE
2
contents.
2
contents.
2
Set CO contents to 10.5 ± 0.3 % and measure
2
combustion and heating air fan speed afterwards
Air Top 3500:
Air Top 5000:
When exceeding the max. motor speed with CO
correctly set, check fuel and exhaust lines for restrictions
in cross section or cloggings. If o.k. replace combustion
and heating air fan according to 9.2.5.
6. After CO
2
for another five minutes and readjust CO
required.
7. Disconnect CO
8. Wait until flashing operating indictor light (LED)
changes to a steady indication.
9. Wait for completion of run-down and switch heater off.
If setting range is not sufficient (e.g. after replacement of
the combustion and heating air fan), repeat setting
procedure once.
If the second attempt of CO
a heater component is defective. Return the heater to
Webasto Thermosysteme GmbH for testing and repair.
6.3 Components Testing
For individual components checks the electrical
connections on the control unit and the component under
test must be disconnected.
6.3.1 Glow Plug / Flame Sensor
Resistance Check
When checking the glow plug/flame sensor with a digital
multimeter the following values should be obtained:
value).
Glow plug / flame sen.: 12 Volt (red)
Resistance at 25° C:
Test current:
6 Functional Checkouts
NOTE
-1
3900 min
-1
5200 min
contents adjustment allow heater to operate
pin from vehicle ground.
2
NOTE
adjustment is unsatisfactory,
2
CAUTION
0.3 ... 0.6 Ω
< 5 mA
max.
max.
value
2
setting as
2
24 Volt (green)
1.18 ... 1.32 Ω
< 5 mA
601