Thermal protector? AC not working.
#1
Thermal protector? AC not working.
Just got a 2002 civic EX. Long story short, mechanic recharged Freon and compressor wouldn't start. Some how he bypass a connection and compressor worked. The ac works perfect super cold in minutes. When he reconnected the wires the way it was the A/C would not work by pressing the A/C button (button lights up). He checked the wiring and came up with a conclusion that a device(another thermal protector? thermostat??) behind the glove compartment that communicate with the front thermal protector is not working. I'm just super frustrated with this issue. Been going back and forth with mechanics and nothing. Checked relays, and fuses Everything good with that. What exactly is behind the glove compartment? Any suggestions? please help. Thanks in advance.
#2
On the 2002 the evaporator thermal control is a thermistor that drives the control panel. I think it is reached from the drivers side. There is also the thermal protector on the compressor. That protector is a switch that should be closed all the time.
#3
The thermal protector switch? how can I confirm that it is closed? and about the evaporator thermal control where exactly is it? what does it look like? what do I check or change? ...first time dealing with this. thanks for the help
#4
Unplug the switch (on the end of the compressor, you may want to remove the power steering pump for access) and measure with an ohmmeter it should be near zero ohms. If it's the type that is wired in series with the clutch coil (not with two small wires) you already know it is good since the compressor ran when jumped.
Also check the pressure switch on the receiver (mounted on left fender I think). For the evaporator temperature circuit you should obtain a service manual and follow the directions to run the control panel self-test, which should detect if the sensor is totally bad. Sensor can be reached under the dash from the driver's side and resistance measured, the proper resistance should be in the service manual.
Plug everything in normally and measure the voltage from one of the pressure switch wires to ground (should not matter which one, since the switch is closed). There should be a voltage there with the engine running and A/C off, then it should drop to near zero volts when you press the A/C button.
Also check the pressure switch on the receiver (mounted on left fender I think). For the evaporator temperature circuit you should obtain a service manual and follow the directions to run the control panel self-test, which should detect if the sensor is totally bad. Sensor can be reached under the dash from the driver's side and resistance measured, the proper resistance should be in the service manual.
Plug everything in normally and measure the voltage from one of the pressure switch wires to ground (should not matter which one, since the switch is closed). There should be a voltage there with the engine running and A/C off, then it should drop to near zero volts when you press the A/C button.
Last edited by mk378; 05-01-2011 at 04:32 AM.
#7
That is OK to do, the protector's only use is to keep the compressor from overheating if someone were to run it with a low charge for a long time. So with it bypassed, should you notice a loss of cooling performance, be sure to disengage the A/C until you can check it out.
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