A/C troubleshooting advice
Discussion
Hi,
The air conditioning (climate) is not working on my Focus (2002). The compressor clutch engages, but disengages again within 10-15 seconds.
I borrowed a top-up bottle of R134a, just to do a pressure check on the low pressure side of the system. I know it doesn't need topping up as the compressor cuts in.
It was a hot day yesterday ~32c, and the static pressure on the low side with the engine off was ~90-95psi. This appears to be about right I learned the low/high side equalises when the engine and A/C is off and I read that the static pressure should almost mirror the ambient temperature in Fahrenheit (89 in this case).
With the engine running and A/C off, the pressure drops to 35-45psi.
When you switch on the A/C the pressure rises to slightly over 100psi, at which point the compressor clutch disengages and the pressure drops back to 35-45 again.
Now comes the guilty admission. It's never had a receiver/drier changed in my ownership (8 years) and no record of it being changed in the first 4-5 years of its life, so it could be the original from new.
The condensor was changed 5 years ago, system vacummed (30 mins) and refilled. I know it should have had the receiver/drier changed at this point (cringe).
The system was regassed two months ago as it had lost 2/3 of the refrigerant as it hadn't been used for 9-10 months. It was vacuumed for 40 mins. The garage that did the work advised that it really ought to have a new receiver/drier.
I have spoken with the garage on the phone and he is pretty certain the receiver drier is blocked.
Looking at the A/C circuit, that diagnosis seems plausible given the short amount of time before the clutch disengages due to excess pressure on the low side. Obviously I haven't had the pressure checked on the high side yet, but does a blocked receiver/drier sound the likely culprit?
The air conditioning (climate) is not working on my Focus (2002). The compressor clutch engages, but disengages again within 10-15 seconds.
I borrowed a top-up bottle of R134a, just to do a pressure check on the low pressure side of the system. I know it doesn't need topping up as the compressor cuts in.
It was a hot day yesterday ~32c, and the static pressure on the low side with the engine off was ~90-95psi. This appears to be about right I learned the low/high side equalises when the engine and A/C is off and I read that the static pressure should almost mirror the ambient temperature in Fahrenheit (89 in this case).
With the engine running and A/C off, the pressure drops to 35-45psi.
When you switch on the A/C the pressure rises to slightly over 100psi, at which point the compressor clutch disengages and the pressure drops back to 35-45 again.
Now comes the guilty admission. It's never had a receiver/drier changed in my ownership (8 years) and no record of it being changed in the first 4-5 years of its life, so it could be the original from new.
The condensor was changed 5 years ago, system vacummed (30 mins) and refilled. I know it should have had the receiver/drier changed at this point (cringe).
The system was regassed two months ago as it had lost 2/3 of the refrigerant as it hadn't been used for 9-10 months. It was vacuumed for 40 mins. The garage that did the work advised that it really ought to have a new receiver/drier.
I have spoken with the garage on the phone and he is pretty certain the receiver drier is blocked.
Looking at the A/C circuit, that diagnosis seems plausible given the short amount of time before the clutch disengages due to excess pressure on the low side. Obviously I haven't had the pressure checked on the high side yet, but does a blocked receiver/drier sound the likely culprit?
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