New Ac system acting up - need advice

[JohnHere]

First, check your Manifold Gauge Set and/or RRR machine, as well as the hoses, to verify no equipment leaks.

At 86°F with a full charge and good condensing, the high side should be around 200 to 220 PSI. Since yours is an aftermarket system, chances are that the specs aren't the same as those for a factory-installed system.

It sounds to me like it's still a bit low on refrigerant. The following procedure has been discussed a few time on this Forum. But to summarize, try adding an ounce at a time while monitoring the pressures and center vent temperature. After adding refrigerant, let the system stabilize for a couple of minutes with the compressor engaged and the engine running at about 1,800 RPM. Then check the gauges and thermometer. You should see the vent temperature start to drop. If the pressures are still rather low, continue adding refrigerant one ounce at a time until the pressures rise into the desired range and the vent temperature begins rising a little, too. At that point, you've reached the approximate optimum charge.

If desired, recover the system, and the RRR machine will tell you exactly how much refrigerant came out. That will be your refrigerant amount, or specification, for next time.

[Moorenycc]

Thank you for this advice!

[tbirdtbird]

Yes, until the low reads 30 at 1500. You are getting there.
Reporting idle pressures does not help us.
Please report as a tech would:
1500 RPM
Hi
Lo
Vent
Ambient
max fan
max cool
doors open (full load).
And none of us would charge a system or measure system performance unless the ambient were at least 80, just for the record.

Oops John beat me to it

[Moorenycc]

UPDATE #2: Quite a bit more refrigerant was added to my system today. I think at least another 6-8ozs today for a total of about 10-12oz more. At 1500 rpms (ac full blast) I was able to get the low side pressure to just about 30psi and high side to 225psi. Ambient temperature outside is 86. Center vent temp is about 45 degrees. The system seems to be working well now. Thank you everyone for your help. I feel like the system is pretty much good to go now. I would have never expected to need some much more refrigerant.

[tbirdtbird]

Your numbers are absolutely perfect, good job!

Another possibility is that the service machine needs calibration.

Enjoy your AC!

[Moorenycc]

Yes. I am thinking that the service machine might be off!

[JohnHere]

UPDATE #2: Quite a bit more refrigerant was added to my system today. I think at least another 6-8ozs today for a total of about 10-12oz more. At 1500 rpms (ac full blast) I was able to get the low side pressure to just about 30psi and high side to 225psi. Ambient temperature outside is 86. Center vent temp is about 45 degrees. The system seems to be working well now.

That IS quite a bit more refrigerant, 44 ounces net weight (2.75 pounds) or three-quarters of a pound more than factory. But if it's cooling well and the pressures look right, great.

Out of curiosity, how much PAG oil did you put in it, and what viscosity?

For reference, the specifications for your vehicle, for a factory-installed system, call for 32 ounces net weight (2.0 pounds) of R-134a, and 6.25 fluid ounces of PAG-100.

[Moorenycc]

I put 6.2oz of page oil. This whole situation was strange to me. I expected to put 32oz of refrigerant in this thing and be done with it. Boy was I wrong.

[Tim]

When you mention the "aftermarket" system, I take that to mean the vehicle never came with A/C from the factory. IS this correct, and you installed a universal compressor, cond, and some form of evaporator system?

[Moorenycc]

It originally had Ac. However, I replaced all the components with aftermarket brand parts (mainly UAC and GPD). I didn't use MOPAR factory parts. The Ac system I took out was 100% original (except the evaporator) believe it or not. The aftermarket condenser, compressor, and liquid line looked different than the MOPAR factory PARTS (they were not identical).