Ac cold one day not the next
- Thread starter tbadalaty
- Start date
tbadalaty
Member
- Car
- Gts
Ac broke help 2009fx
2009 fx35 Sunday ac cold today just outside air temerature. compressor and clutch engage duct work changes floor vent defroster. Odd. Did notice a ring of rubber coming out around compressor pulley and clutch looks odd? Let me know any ideas <br />
<br />
Thanks all<br />
<br />
Troy<br/>
2009 fx35 Sunday ac cold today just outside air temerature. compressor and clutch engage duct work changes floor vent defroster. Odd. Did notice a ring of rubber coming out around compressor pulley and clutch looks odd? Let me know any ideas <br />
<br />
Thanks all<br />
<br />
Troy<br/>
Can you check the pressure? If you don't have the gauge (most don't) take it to an AC shop and they can diagnose what is happening. It could be as simple as you don't have enough refrigerant in the system so it won't turn on all the time. There is a low pressure safety switch and the system pressure is temperature dependent so if pressure is low it may turn on intermittently. Or worst case, your compressor could be toast. Is the compressor noisy?
No one can diagnose over the internet, especially without any details. So take it to a shop or you can buy the gauges at Harbor Freight for ~$55.
No one can diagnose over the internet, especially without any details. So take it to a shop or you can buy the gauges at Harbor Freight for ~$55.
Mcontrols
Member
- Car
- 2009 FX35 RWD
- Name
- Mike
DIY...open your hood, turn AC off and start the engine. Look at the compressor, the clutch will not be engaged so it won't be spinning. Now turn on the AC and set to coldest setting. Now look at the compressor, the clutch should be engaged and the entire pully be spinning. After a few minutes look at the lines attached to the compressor. One of them, the larger one, should be cold and have condensation on it. Trace that line back to the firewall and you should see where the line goes into the car. It should be very cold and wet. If the compressor is engaged and the line is not real cold then you likely need refrigerant. An AC shop can diagnose your system in a few minutes.
MC
MC
I believe the FX uses a variable displacement compressor so it's not off or on like old style setups. It may be spinning but not doing much if there is no demand.
Only real way to diagnose is with a hi/lo gauge. So either spend $55 at Harbor Freight or take it to a shop.
Low side should be somewhere between 35 and 45psi. I don't think the compressor will even engage below 25psi.
High side will be dependent on temperature, but it's usually 2.2-2.5x the ambient temperature. So if it's 80 degrees out, high side should read ~180-200psi.
High side and low side will equalize if the AC is off. So if you turn the AC on and the high/low pressures are the same, your compressor isn't kicking in for some reason. If there is a blockage on the high side in evaporator or expansion valve or pinched line, this will cause high side pressure to build up too high. If that happens, it would trigger a safety cutoff and your AC will stop working. That may be a reason you have AC some days but not others.
If the low side pressure is low when the system is off, turning the AC on can cause it to drop further as the compressor moves refrigerant through the system. If that pressure drop takes it below 25psi, it can cut off.
Only real way to diagnose is with a hi/lo gauge. So either spend $55 at Harbor Freight or take it to a shop.
Low side should be somewhere between 35 and 45psi. I don't think the compressor will even engage below 25psi.
High side will be dependent on temperature, but it's usually 2.2-2.5x the ambient temperature. So if it's 80 degrees out, high side should read ~180-200psi.
High side and low side will equalize if the AC is off. So if you turn the AC on and the high/low pressures are the same, your compressor isn't kicking in for some reason. If there is a blockage on the high side in evaporator or expansion valve or pinched line, this will cause high side pressure to build up too high. If that happens, it would trigger a safety cutoff and your AC will stop working. That may be a reason you have AC some days but not others.
If the low side pressure is low when the system is off, turning the AC on can cause it to drop further as the compressor moves refrigerant through the system. If that pressure drop takes it below 25psi, it can cut off.
Mcontrols
Member
- Car
- 2009 FX35 RWD
- Name
- Mike
It is a variable displacement compressor but the clutch does not engage when the AC is turned off. That's why I said look at it with the engine running and the AC is OFF. If his clutch is working he will see a difference because the clutch is engaged full time when the AC is turned ON.....unless the low refrigerant or low temp safety cuts it off. Wanted to establish if compressor us running. If it is and air isn't cold solution simple, add gas.
MC
MC