If your car’s AC compressor only works when relay is bypassed, you’re in for a hot summer. Before we discuss the main problem, a few other observations can be explained. Such as the fact that the weather is getting hot and your air conditioner needs to be fixed.
You came to the conclusion that the compressor and relay are in good shape. Nothing happens when you turn on the car’s switch. But if you remove the relay and insert a jumper, everything works. I purchased a new relay and installed it, but the issue persists. Don’t worry, we’ve got a few tips to help keep you cool.
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Why Does Your 1 AC Compressor Only Work When The Relay is Bypassed?
There are a few reasons why does your 1 AC compressor only work when the relay is bypassed. The most common reason is that the compressor itself is faulty and needs to be replaced. Another possibility is that the compressor isn’t getting enough power, so the relay is being used to bypass the system and send power directly to the compressor. If this is the case, you’ll need to check the wiring to see if there’s a problem that’s preventing the compressor from getting enough power.
In some cases, a faulty relay can also cause this problem. If you suspect that the relay is at fault, you can try replacing it to see if that fixes the problem. Moreover, your AC compressor only works when relay is bypassed.
How Do I Fix your 1 AC Compressor Only Works When Relay Is Bypassed?
There are a few possible reasons why your1 AC compressor only works when relay is bypassed. The most common reason is that the relay is faulty and needs to be replaced. Another possibility is that there is a problem with the wiring between the relay and the compressor. If the wiring is damaged, it will need to be repaired or replaced.
What Are the Possible Causes of This Problem?
There are several possible causes for this problem when your AC compressor only works when relay is bypassed:
- The AC compressor itself could be faulty and need to be replaced.
- The AC compressor clutch could be damaged or stuck, preventing the compressor from turning on.
- The AC compressor relay could be faulty and need to be replaced.
- There could be a problem with the AC compressor wiring harness.
How Can I Prevent This Problem From Happening Again?
When your AC compressor only works when the relay is bypassed, it’s likely that the problem lies in the electrical system. The first thing you should do is check the fuse and make sure it’s not blown.
If the fuse is good, then you should check the connection at the compressor itself. It’s possible that the compressor is getting power, but the connection is loose and needs to be tightened.
If neither of those solutions solves the problem, then you may need to replace the AC compressor relay. This part is relatively inexpensive, so it’s a good idea to replace it even if you’re not sure it’s the cause of the problem. Once you’ve replaced the relay, you should also flush and recharge the AC system to get rid of any debris that may have caused the original problem.
Control Circuit for the AC Clutch Relay
The clutch on the AC compressor is in charge of pressurizing the A/C system in your car. It is attached to a relay that enables the powertrain control module (PCM) or engine control module (ECM) to turn on or off the air conditioning. The air conditioning system may operate and circulate cool air around the cabin as soon as the compressor clutch is engaged. A P0645 error code could indicate the problem of why the AC compressor only works when relay is bypassed.
The PCM’s diagnostics will record a P0645 code if it is unable to regulate the A/C compressor clutch relay.
What is P0645 Code for AC Compressor Only Works When Relay Is Bypassed
The “AC Clutch Relay Control Circuit” is indicated by the Diagnostic Trouble Code (DTC) P0645. Through the control circuit driver, the PCM regulates the A/C compressor clutch relay. The relay control circuit’s ground is provided by this solid-state component. By permitting the module to control the clutch’s on/off state, the driver can activate the compressor and supply power to the clutch. The A/C compressor clutch relay control circuit may contain several control modules, depending on the vehicle.
The PCM is constantly monitoring a fault line in the control circuit driver. The voltage of the control circuit will be close to 0 volts when the controller engages the clutch. It will be compatible with the battery’s positive voltage, which drives the A/C compressor clutch.
AC Compressor Only Works When Relay Is Bypassed When the Low-Pressure Switch Is Activated
You’ve discovered a way to get around the low-pressure switch and fix your broken system. It indicates that either the system’s pressure is too low or the switch is broken and supplying the incorrect ohms.
Your switch is supplying the right ohms according to your measurement. The jumper you are using, which works, has the same ohms as your switch. So, it doesn’t seem like you are avoiding a problem.
Simply leave the jumper you’re wearing in its current location. The potential problem is that without the LP switch to turn off the system if your pressure drops, you risk damaging the compressor.
What Should You Do if My AC Compressor Stops Working?
If your AC compressor stops working, there are a few potential causes.
- First, check to see if the compressor is receiving power. If it is, then the problem may be with the compressor itself.
- If the compressor is not receiving power, then the problem may be with the AC system’s electrical relay. To check this, you can bypass the relay by connecting the compressor’s wire directly to the battery.
- If the compressor starts working when you do this, then you will need to replace the relay.
How Can I Troubleshoot This Problem?
There are a few things that you can do in order to troubleshoot this problem:
- First, check the fuse that goes to the AC compressor. If this fuse is blown, then it will need to be replaced before the compressor will work again.
- Next, check the wiring going to the AC compressor. Whenever AC compressor only works when relay is bypassed or If there are any loose wires or if the insulation is damaged, then this could be causing the problem. Tighten all of the connections and replace any damaged wiring.
- Finally, check the AC compressor itself. If it is not working, then it will need to be replaced.
What Are the Common Symptoms of This Problem?
The most common symptom of this problem is that the ac compressor only works when the relay is bypassed. This can be caused by a number of things, but the most likely cause is a problem with the relay itself. If you suspect that this is the problem, it’s a good idea to take your car to a mechanic or car dealership to have them check it out.
How Can I Resolve This Problem?
The AC compressor only works when the relay is bypassed. This could be caused by a number of things, such as a faulty relay, a faulty AC compressor, or a wiring problem. You will need to troubleshoot each of these potential causes to determine which is causing the problem.
FAQs
Q. What Stops the Clutch of an AC Compressor From Engaging?
A blown fuse, an opening in the wire leading to the clutch coil, a faulty clutch coil, a broken ground, or a low-pressure lockout could all be to blame if the clutch doesn’t engage. This can be one of the reasons that the AC compressor only works when relay is bypassed. The low-pressure switch and the evaporator temperature sensor can both turn on and off the compressor clutch relay in some automobiles.
Q. What Signs Might Point to a Defective Part of the AC Compressor Only Works When Relay Is Bypassed?
The AC system won’t work since the AC compressor won’t have power. Intermittent AC compressor operation impairs or disrupts cooling performance. Then the AC compressor only works when relay is bypassed.
Q. What Module Manages the Relay for the AC Compressor?
The control circuit driver, under the direction of the PCM, drives the A/C compressor clutch relay. This solid-state component provides the ground for the relay control circuit. The driver can turn on the compressor and power the clutch by giving the module control over the clutch’s on/off state.
Conclusion
If your AC compressor only works when relay is bypassed then you should pay attention to every step of the process when testing the AC compressor in your car. However, depending on how your diagnosis turns out, all you need to do is use a multimeter to verify the power supply to the AC compressor clutch and pressure switches.
If you don’t receive the desired outcomes from these components, you then fix or replace them. The best course of action is to completely replace the AC compressor.
