Mercedes-Benz Sprinter 2003 Manual page 94

CABIN HEATER
FAN STAGE 1 RELAY CONTROL SHORTED —
TEST
2 WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater harness connector.
Remove the substitute Fan Stage 1 Relay from the relay center.
Measure the resistance between ground and the Fan Stage 1 Relay High Side Control
circuit.
Is the resistance below 10K ohms?
Yes → Repair the Fan Stage 1 Relay High Side Control circuit for a short
→ Go To 3
No
3 WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Cabin Heater harness connector.
Remove the Fan Stage 1 Relay from the relay center.
Measure the resistance between the Fan Stage 1 Relay High Side Control circuit and
the Ground circuit (Fan Stage 1 Relay connector terminal 86 and 85).
Is the resistance below 10K ohms?
Yes → Repair the Fan Stage 1 Relay High Side Control circuit for a short
→ Replace the Cabin Heater Assembly in accordance with the
No
ACTION
to ground. Reinstall the original Fan Stage 1 Relay.
Perform HEATER VERIFICATION TEST - VER 1.
to the Ground circuit.
Perform HEATER VERIFICATION TEST - VER 1.
Service Information.
Perform HEATER VERIFICATION TEST - VER 1.
Continued
86
APPLICABILITY
All
All