A/C Clutch not engaging

Mxzx · 08-09-2021, 08:47 AM

Any ideas on which wires to jump on pressure switch?

SonicVQ · 08-09-2021, 09:42 AM

I'm glad you didn't try to jump any wires... It isn't a switch, but a pressure sensor.

I suspect your A/C refrigerant is low and the ECU isn't turning on the A/C clutch to prevent damage. If the pressure sensor detects less than 17 psi or more than 452 psi, the ECU will not turn on the compressor.

If your scan tool has advanced diagnostics, it can show you the voltage, or use a meter to check. It should be between 1-4 volts.

The center wire is the 5 volt sensor output. The outside wires are ground and 5 volts. Use a meter to determine the polarity and check the voltage between the sensor ground and the centre wire.

Spooler · 08-09-2021, 02:52 PM

Quote:

Originally Posted by SonicVQ

I'm glad you didn't try to jump any wires... It isn't a switch, but a pressure sensor.

I suspect your A/C refrigerant is low and the ECU isn't turning on the A/C clutch to prevent damage. If the pressure sensor detects less than 17 psi or more than 452 psi, the ECU will not turn on the compressor.

If your scan tool has advanced diagnostics, it can show you the voltage, or use a meter to check. It should be between 1-4 volts.

The center wire is the 5 volt sensor output. The outside wires are ground and 5 volts. Use a meter to determine the polarity and check the voltage between the sensor ground and the centre wire.

Ah, they changed them up. Time to get out a gauge set and check the charge.

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08-09-2021, 08:47 AM	#1 (permalink)
Mxzx Base Member Join Date: Oct 2020 Location: KY Posts: 28 Drives: 2011 370Z Nismo Rep Power: 5	Any ideas on which wires to jump on pressure switch?

08-09-2021, 09:42 AM	#2 (permalink)
SonicVQ Base Member Join Date: Jan 2016 Location: Ontario Posts: 230 Drives: G37 Sport Rep Power: 6721	I'm glad you didn't try to jump any wires... It isn't a switch, but a pressure sensor. I suspect your A/C refrigerant is low and the ECU isn't turning on the A/C clutch to prevent damage. If the pressure sensor detects less than 17 psi or more than 452 psi, the ECU will not turn on the compressor. If your scan tool has advanced diagnostics, it can show you the voltage, or use a meter to check. It should be between 1-4 volts. The center wire is the 5 volt sensor output. The outside wires are ground and 5 volts. Use a meter to determine the polarity and check the voltage between the sensor ground and the centre wire.