Webasto Air Top 2000 D Service And Repair Manual page 19

Air Top 2000
5. Troubleshooting
5.1 General
This section describes troubleshooting procedures for
the Air Heater Air Top 2000 and Air Top 2000 Diagnosis.
A malfunction in air heaters Air Top 2000 Diagnosis out-
puts an error code to the display of the combination or
standard timer. When equipped with a control element
the operating indicator flashes. In addition a heater chec-
kout may be performed using a personal computer (refer
to operating instructions PC air heater diagnosis).
CAUTION
Troubleshooting requires profound knowledge about
structure and theory of operation of heater components
and may only be performed by skilled personnel.
In cases of doubt refer to Sections 2 or 3 for functional
interrelations.
Only for TRS operation
After a TRS switch-off or power application by vehicle
main power switch operation and the control element to
"ON", the control unit will be in "error lockout".
Prior to reactivation the control element must be set to
"OFF" or the instant heat switch on the combination or
standard timer be operated.
Failure Symptom
Air heater switches
off automatically
Heater expels black fumes
NOTE
Probable Cause
No combustion after start or repeat
start
Flame extinguishes during
operation
Heater overheats
Operation indication flashes
Vehicle electrical
system voltage too low
Combustion air and/or
exhaust ducting blocked
Fig. 501 General Failure Symptoms
CAUTION
Troubleshooting is normally limited to the isolation of
defective components.
The following causes for trouble are not considered and
should always be checked for to exclude them as cause
for trouble:
corrosion on connector
loose contact on connector
wrong crimping on connector
corrosion on electrical wiring and fuses
corrosion on battery terminals
If individual components are checked, the control unit
electrical connections must be disconnected.
After any correction of a failure a functional test has to
be performed in the vehicle.
5.2 General Failure Symptoms
The following table (Fig. 501) lists the possible failure
symptoms.
Remedy
Switch off heater momentarily and
switch on once again
Switch off heater momentarily and
switch on once again
Check heat air ducting for
obstructions, allow heater to cool
down, switch off heater momentarily
and switch on once again
Charge battery
Switch off heater momentarily and
switch on once again
Check combustion and exhaust
ducting for obstructions
5 Troubleshooting
501