So, I recently had my A/C redone from a local reputable tech who deals specifically with old car A/C. The A/C works fine, it's just not very cold. I had him put original R12 in it. Just about everything was replaced except the evaporator Is it the evaporator? Or can there be airflow blockage somewhere causing this?

Any suggestions of what I can do to help the problem short of discharging the A/C would be appreciated.

If it comes to replacing the evaporator...well...I guess I'll have to save my money, pay him to recover the freon and install the evaporator, and be done with it, but I'd like to see if it's something simple.

 

I've been doing commercial HVAC systems for years, but also know car systems too. I doubt it's the evap, and probably the shop not putting enough, or to much R-12 back in. If done properly, the suction(larger line) on the evap should be sweating, if you can see any part of it not covered with black gunk. Really not rocket science recharging these systems, as usually a refrigerant weight listed on the compressor label, and the shop should've used a scale putting R-12 back in. Would've been a good idea giving the system a UV dye shot too, for scanning leaks with a UV light later. A6 compressor shaft seals are known for being real leakers. Think 72's still had AC system liquid site glasses you can see through a hole in front rad support plate to the left. If bubbling or not solid liquid, probably undercharged. If solid with things still not working properly, maybe overcharged, but who knows. Oh well, guess I know more about automotive AC than first thought.

 

Need the following to help out:

Ambient temperature
Vent temperature
High side pressure
Low side pressure
Blower speed
Engine RPM
Fan type

I assume stock A6 compressor with POA valve.

I have heard many a techs not putting enough Freon in because they do not know what pressure to have and or not evacuating enough prior to charge.

 

Would upgrading the blower motor help and is this possible without too many modifications?

 

I already looked into this and there are no common mods available.
These fans seem to put out a good airflow, providing the evap core is clean.
The cores get plugged over this many years of dust and dirt and need a good external washing. If the core leaks, the oil will attract more crap and really plug it up. A plugged evap = low airflow.

 

Agree with Rob. If evap is clean, a bigger fan will have higher A/C temps as increased volume of air moves across the same cooling capacity. What does your A/C tech have to say? Sounds more like freon levels as DeltaPace77 explained.