Atc Switch And Circuit Test; Defog/Defrost Switch And Circuit Test - New Holland T8010 Manual

ATC Switch and Circuit Test

Steps and Test Point
1. Disconnect ATC switch from harness. ATC switch
to "AUTO." Measure resistance between pins 4
and 5 on switch? Less than 1 ohm?
2. Measure resistance from pin 5 at the ATC harness
to terminal ground. Less than 1 ohm?
3. Keyswitch ON. Is 5V present between pin 4 and
chassis ground at the harness connector.
4. Is 5V present between pin 26 at the controller and
chassis ground?

Defog/Defrost Switch and Circuit Test

Steps and Test Point
1. Disconnect DEFOG/DEFROST
har ness. DEFOG/DEFROST switch to "ON."
Measure resistance between pins 2 and 3 on
switch? Less than 1 ohm?
2. Measure resistance from pin 2 at the DEFOG/
DEFROST harness to terminal ground. Less than
1 ohm?
3. Keyswitch ON. Is 5V present between pin 3 and
chassis ground at the harness connector.
4. Keyswitch ON. Is 5V present between pin 31 at
controller and chassis ground at the harness
connector.
Section 50 - Climate Control - Chapter 1
YES - Go to next Step.
NO - Replace switch.
YES - Go to next Step.
NO - Locate and repair open condition between pin 5
and ground.
YES - Go to next Step.
NO - Go to Step 5.
YES - Locate and repair open condition between pin
26 at controller through C139-L and pin 4 at the
switch.
NO - Test the controller. See ATC Controller Tests in
this Section.
switch from YES - Go to next Step.
NO - Replace switch.
YES - Go to next Step.
NO - Locate and repair open condition between pin 5
and ground.
YES - Go to next Step.
NO - Go to Step 5.
YES - Locate and repair open condition between pin 3
at controller through CJ6R-L and pin 4 at the switch.
NO - Test the controller. See ATC Controller Tests in
this Section.
50-1-57
Corrective Actions
Corrective Actions