Why is my a / C relay not grounding?
Why is my a / C relay not grounding?
The PCM does not commands the A/C relay for some reason, either the output is shut = new PCM or does not receive the command from the Climate control module (yeah I know you replaced the module). 2. The wire from pin 27 of the C1 connector on the PCM does not makes good contact on the PCM connector or on the relay stand (hope that is your problem).
Can we switch ground in relay-electrical engineering Stack Exchange?
If you have only a positive signal for “horn” then you can add a small 12V relay to operate the horn relay or add a transistor (and a resistor and a flyback diode). Otherwise there is no way to do it with a 3-pin relay as shown. Thanks for contributing an answer to Electrical Engineering Stack Exchange!
Why is my AC compressor relay not working?
As for your relay ground setup thing, the clutch will be engaged ALL THE TIME your ignition key is in START or RUN (i.e. as long as your engine is running). And as long as your Climate Module controls everything else (like the fan) then I see no issue with sending the A/C ON request to the PCM. Is a software thing, is either working or not.
How is the a / C clutch connected to the ground?
When the command is received from the Climate Module, the pressure switches are OK and the engine is in a safe REV range the PCM makes a well informed decision to engage the A/C Clutch as long as is needed and safe. This is achieved by connecting the A/C output to the ground (Pin 27 on C1 connector).
How is the a / C relay connected to the ground?
This input is connected to D1 pin of the A/C relay via a DK GRN/WHT wire. It is exactly the pin you connected to the ground by bypassing the PCM. Now since you say the A/C kicks in the both your A/C Low Pressure and your A/C High Pressure Switches are closed (as in the refrigerant pressure is fine).
What to do if your AC compressor relay is not grounding?
But before splashing $100 on a replacement PCM you better be DARM sure the relay control ground wire is making contact with the above mentioned pin on the PCM. You can always use a meter to check if the PCM is working. Just connect one probe of the meter to the battery positive voltage and the other to pin 27 of the PCM.
If you have only a positive signal for “horn” then you can add a small 12V relay to operate the horn relay or add a transistor (and a resistor and a flyback diode). Otherwise there is no way to do it with a 3-pin relay as shown. Thanks for contributing an answer to Electrical Engineering Stack Exchange!
Where is the relay on an AC compressor?
Basically when applying + to C3 (from the Cruise Fuse thorough the serially connected pressure switches) and (-) to the D1 pin (from pin 27 on C1 connector of the PCM – software algorithm) the relay closes the contact between pin D3 (from the A/C fuse – ORN wire) and pin C1 (to the A/C Clutch – DK GRN/WHT wire) engaging the compressor.
The PCM does not commands the A/C relay for some reason, either the output is shut = new PCM or does not receive the command from the Climate control module (yeah I know you replaced the module). 2. The wire from pin 27 of the C1 connector on the PCM does not makes good contact on the PCM connector or on the relay stand (hope that is your problem).
As for your relay ground setup thing, the clutch will be engaged ALL THE TIME your ignition key is in START or RUN (i.e. as long as your engine is running). And as long as your Climate Module controls everything else (like the fan) then I see no issue with sending the A/C ON request to the PCM. Is a software thing, is either working or not.
Why is my a / C not working on my Chevy Silverado?
Subject: Air Conditioning (A/C) Blows Warm Air Intermittently. This condition may be caused by the A/C compressor clutch cycling out early when the low pressure side reaches approximately 380 kPa (55 psi). The fix is to bring the vehicle to the dealer to have the latest software installed into the vehicle.
Which is the control pin for the a / C CLUTCH?
You connected the PCM pin 27 on C1 connector to ground (that is the control pin for the A/C clutch). The PCM is the one controlling the A/C clutch based on the data received from the Climate Control module and the following two sensors: A/C High Pressure Switch and A/C Refrigerant low pressure switch.
What do you need to know about clutch relays?
What is a clutch relay? A relay is a device that allows you to control high amperage circuit from low amperage circuit. Automotive switches and electronics are wired to relays since they aren�t designed to handle the arcing and high current demand required in some circuits. How a relay works
How to wire a 5 pin automotive relay?
How to Wire a 5 Pin Automotive Relay. Pins 87/30/85/86/87a . Bosch Style. Fans / Fuel Pump / Lights – YouTube How to Wire a 5 Pin Automotive Relay.
You connected the PCM pin 27 on C1 connector to ground (that is the control pin for the A/C clutch). The PCM is the one controlling the A/C clutch based on the data received from the Climate Control module and the following two sensors: A/C High Pressure Switch and A/C Refrigerant low pressure switch.
What is a clutch relay? A relay is a device that allows you to control high amperage circuit from low amperage circuit. Automotive switches and electronics are wired to relays since they aren�t designed to handle the arcing and high current demand required in some circuits. How a relay works
How is the compressor clutch relay turned on and off?
In some vehicles the compressor clutch relay is turned on and off by the low pressure switch and the evaporator temperature sensor. In a computer controlled system, the compressor clutch relay is grounded by the computer. If the fuse is good, disconnect the electrical connector from the compressor clutch coil.
When to move on to the clutch relay?
Move on to the clutch relay if the fuse turns out fine. In a few car models, the power of the air conditioning system flows from the AC switch to the fuse before being transmitted to the clutch oil through the low-pressure evaporator temperature. You have to make sure that the compressor has enough oil to function properly.
What to do if your air conditioner clutch does not engage?
If the clutch doesn’t engage, the air conditioning compressor can’t pump refrigerant. So start your diagnosis by determining if the compressor clutch works. Turn the air conditioning controls to MAX AC and start the engine. Then look at the front of the compressor clutch.
When the command is received from the Climate Module, the pressure switches are OK and the engine is in a safe REV range the PCM makes a well informed decision to engage the A/C Clutch as long as is needed and safe. This is achieved by connecting the A/C output to the ground (Pin 27 on C1 connector).
Move on to the clutch relay if the fuse turns out fine. In a few car models, the power of the air conditioning system flows from the AC switch to the fuse before being transmitted to the clutch oil through the low-pressure evaporator temperature. You have to make sure that the compressor has enough oil to function properly.
If the clutch doesn’t engage, the air conditioning compressor can’t pump refrigerant. So start your diagnosis by determining if the compressor clutch works. Turn the air conditioning controls to MAX AC and start the engine. Then look at the front of the compressor clutch.
