Unable to recharge A/C

CNSUTTER

MEMBER
2009 HONDA CIVIC HYBRID
AUTOMATIC
125,000 MILES

Air conditioning blows warm, not working at all. I purchased an A/C recharge kit (pure R134a without any dyes or sealants). When I hook everything up, the compressor seems to be engaged (center turns). The pressure on the low side port reads about 15 psi. When I pull the trigger, it doesn't seem like anything happens. I have sat and held the trigger for minutes on end (moving can as instructed) and the can still feels full and the pressure has not moved. I thought maybe it was a defective can or hose/gauge and bought different ones and go the same result.

When I turn the A/C off, the compressor disengages properly and low side pressure goes up to 100psi + as expected. With A/C on, the clutch engages again.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Hi cnsutter,

It sounds like you are performing the procedure correctly. I attached some links to this post for your review just to make sure.

Assuming you prove out that you are in fact performing this correctly, the next step is to find out exactly what your pressures are, high and low side while the engine is running and AC is on. I see where you said the low side is 15 with the compressor appearing to be engaged and then when it is off, it disengages and it goes to 100. This appears to be normal operation.

If you don't have a set of AC gauges you can rent them for free at most parts stores like auto zone. Do not trust the gauge that comes on the bottle of Freon that you purchased. We need an actual set of gauges.

Once you have them hooked up, I want you to note what the pressures are with the engine off. Then I want you to turn the engine on and turn on the AC. Note what your pressures are with the compressor running. The compressor should cycle on and off so I want you to note what the pressures are when the compressor cycles off. If it does not cycle, that is not necessarily an issue so just not that for future reference.

Lastly, when the compressor is running, I want you to monitor your AC lines and see if they are getting cold. The video in the "how to add Freon" points out where you need to check. Are the lines getting cold or do they stay warm?

If they get cold and your blower is working then we could be dealing with a blend door issue inside your HVAC housing. Meaning the evaporator is getting cold inside the housing but the air is being directed over the heater core which is heating your air rather than blowing cold air.

In general, all the air goes over the evaporator regardless of HVAC setting because we need to keep the moisture out of the cabin because fogging windows is not good. Only when you command heat do they redirect the air after it goes through the evaporator to go over the heater core so that the dehumidified air is then heated.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/replace-air-conditioner-compressor

Let me know when you get those pressures and we can go from there.

Kenny