Electrical Test; High Pressure Switch And Circuit Test - New Holland T8010 Manual

Electrical Test

Refer to Schematic Sections 60 through 62 at the end of this section.
Power and Ground
With high pressure switch activation, 5V is present at pin 33 at controller and pin 1 at the switch. The switch is
grounded to the chassis.
With low pressure switch activation, 5V is present at pin 35 at the controller and pin B at the switch. The switch is
grounded to 36 at the controller.
With no pressure switch activation, both circuits test 0.0V at the switch and at the controller.

High Pressure Switch and Circuit Test

Steps and Test Point
1. Refer to A/C Troubleshooting Foldout and follow
the conditions for performance testing. Install A/C
high and low side pressure gauges. High reading
above 400 psi ± 10 psi (2758 kPa ± 69 kPa)?
2. Shut off the tractor. Disconnect the switch from the
harness and the unit. Check that switch is closed
across pins A and B .
3. Reinstall the switch in the unit; do not reconnect
the harness. Keyswitch ON and ATC switch to "A."
Is 5V present at pin B at the har ness to the
switch?
4. Keyswitch OFF. Measure resistance from pin 2 at
the switch to ground. Less than 1 ohm?
5. Keyswitch ON and ATC switch to "AUTO." Is 5V
present at pin D1 at the controller?
Section 50 - Climate Control - Chapter 1
Y E S - Pe r fo r m c o r r e c t i v e a c t i o n s f r o m A / C
Troubleshooting Foldout.
NO - Go to next Step.
OK - Go to next Step.
NOT OK - Replace switch.
YES - Go to next Step.
NO - Go to Step 5.
YES - Go to next Step.
NO - Locate open condition and repair between pin A
and ground.
YES - Locate open condition and repair between CJ8-
34 and pin 1 at the switch.
NO - Test the controller. See ATC Controller Tests in
this section.
50-1-41
Corrective Actions