New Holland 16130 – Cab Climate Control Module: Low Pressure Switch (+) Input Shorted to Power

A short circuit has been detected on the input of the low pressure switch, specifically related to the power supply connection. The signal wire from the low-pressure switch to the control module has made an improper connection to a power source, such as a 12-volt wire. This causes the control module to detect a constant, high voltage instead of a variable signal or normal open/closed state, preventing it from correctly monitoring the pressure of the transmission, hydraulics, or air conditioning system.

• T5 Series
• T6 Series
• T6050
• T7.200
• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• T8 Series
• Puma Series

1. 1

   Verify static refrigerant pressure using a manifold gauge set (pressure below ~25 PSI indicates a leak, which will prevent compressor engagement)

2. 2

   Visually inspect the wiring harness and electrical connector at the low-pressure switch for damage, rubbed insulation, corrosion, or moisture

3. 3

   Check for power at the switch connector using a multimeter with the key on and A/C activated (both pins showing voltage confirms a short to power)

4. 4

   Test the low-pressure switch for internal failure by checking for continuity across its terminals (should have continuity if system pressure is adequate)

1. 1

   Disconnect battery

   Disconnect the vehicle's battery to prevent electrical shorts during diagnosis and repair.

2. 2

   Locate the low-pressure switch

   Find the switch on the A/C low-side service port, receiver-drier (accumulator), or low-pressure refrigerant line.

3. 3

   Isolate the fault

   Disconnect the switch connector. Turn the key to 'ON' (engine off). Check for voltage on the harness-side pins. Voltage on the signal wire confirms a short to power in the harness.

4. 4

   Trace and repair wiring

   If a short is confirmed, trace the harness back to the control module. Locate chafed, pinched, or melted areas. Splice in a new wire section, insulate properly, and secure away from damage sources.

5. 5

   Replace low-pressure switch

   If the wiring is intact and diagnostic tests indicate an internal switch failure, unscrew the old switch and install a new one into the service port.

6. 6

   Clear codes and test

   Reconnect the battery, clear fault codes using the monitor or a service tool, turn on the A/C, and verify the compressor engages and cools.