Mercedes Benz Actors mp4 | MBA A.c Wiring Air Conditioning Compressor not working port-2

Introduction

In this part two video series about the MP4 AC, we delve into the workings of the air conditioning compressor, focusing specifically on how the clutch engages and how the system detects the presence of refrigerant gas. Understanding the wiring of the gas pressure switch is critical for diagnosing whether the compressor should operate.

Compressor Clutch Activation

To start, the activation of the compressor clutch begins with the vehicle's AC switch, referred to as 'XV'. Current initiates from pin N to the coupler (pin 31), which is key to this process. The coupler contains a total of 15 pins, and we’ll highlight pin number 3 as it directly connects to our compressor. The wire from the AC switch travels to the clutch, with one wire serving as the positive connection, while the other serves as ground. This process allows the clutch to engage and start the cooling cycle.

It's important to understand the path of the compressor wire. When the AC is not functioning correctly, it's essential to trace back to the source. The wire arrives from the panel switch to the coupler, with specific pin numbers leading to the compressor’s magnetic clutch. By pinpointing these connections, you can troubleshoot electrical issues more effectively.

Pressure Switch Wiring

In addition to the clutch, we must also examine the pressure switch, designated as 'V33'. This component monitors the refrigerant gas levels in the system, determining if there’s adequate gas for the AC to function. The pressure switch has three wires that connect back to the primary unit. The flow of signals and power through these wires is critical for optimal AC performance.

The voltage measured at the pressure switch serves as an indication of system functionality. When testing with a multimeter, it’s important to confirm that the expected 5 volts are present. If the voltage is absent or incorrect, fault tracing in the wiring may be necessary. The pressure switch ties into the larger system, sending signals that determine whether the compressor engages.

Final Notes

The airflow and cooling ability of the AC depend heavily on these interconnected systems. Understanding the schematic of the wiring from the switch to the pressure and compressor is vital in identifying faults in the AC system. Without sufficient refrigerant levels, the switch will inhibit the compressor from engaging, thereby preventing any cooling action.

Before concluding, remember that this is a simplified overview meant for educational purposes. If issues persist, professional diagnostics may be required to address underlying problems effectively.

By understanding these components and their connections, you can troubleshoot and resolve common AC problems with greater confidence.

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Keyword

Keywords: Mercedes Benz, MP4 AC, HVAC wiring, compressor clutch, gas pressure switch, electrical troubleshooting, car air conditioning, automotive repair, circuit diagrams.

FAQ

Q1: What activates the AC compressor clutch in a Mercedes Benz MP4?
A1: The compressor clutch is activated when the AC switch (XV) sends current through the wiring to the coupler, which connects directly to the clutch circuit.

Q2: What is the purpose of the gas pressure switch?
A2: The gas pressure switch monitors refrigerant levels in the AC system and determines whether the compressor should engage based on the gas presence.

Q3: How does one test the voltage at the pressure switch?
A3: Using a multimeter, check for 5 volts at the designated pin on the pressure switch. This helps confirm whether the system is functioning correctly.

Q4: What happens if the AC system does not have enough refrigerant gas?
A4: If the refrigerant level is low, the pressure switch will prevent the compressor from turning on, thus stopping the cooling process.

Q5: Where can I find the wiring details for the MP4 AC compressor?
A5: Wiring details are typically found in service manuals or can be traced via the vehicle's electrical schematics, which highlight connections and pin numbers.