System Function Tests Preparation START HERE

The system function tests allow testing of individual components and circuits without removing from vehicle using special Mercedes Benz adapter or comparable after market tester.

Automatic Climate Control (ACC) Test Adapter:

ACC Switching Control Units:

1. Remove glove box.
2. Connect ACC adapter by pulling 12 pin plug from electronic switching unit (9) for temperature control and connect to adapter. Yellow test card (issue October 1980) must be used.
3. Connect adapter to volt/ohm measuring instrument.

NOTES:
- During electric test on 2 pin plug of monovalve (with voltmeter, test lamp), be sure to avoid a short. This may destroy the electronic switching unit for temperature control.
- Perform tests in the event of unknown cause of trouble, customer complaints which are not clearly expressed, and follow repairs for guaranteeing all functions.
- Prior to starting system tests, check all fuses for ACC, auxiliary fan, and blower.
- It is recommended to perform manual (visual) function tests of air flaps. SEE Manual (Visual) Function Tests. Manual and Visual Function Test of Automatic Climate Control

WIRING DIAGRAM COLOR CODE
LEGEND
ge = Yellow
gn = Green
gr = Gray
rt = Red
ws = White
hbl = Light Blue
sw = Black