Greetings, Is it possible for air to blow too cold from the center vent after converting from R-12 to R-134A? I just converted my 1993 Honda Accord. A technician pulled as vacuum for 30', added exactly 28 oz of R-134A (the lower limit of R-12 listed on the under hood plate) & told me that oil would not be necessary because the car was so old that there was probably enough mineral oil impregnated in all the parts to maintain adequate lubrication. He said these conversions could fail immediately, in a week or whenever. There were no guarantees. After a few days & research, I added a can of 2 oz Ester oil with 2 oz R-134A to give some circulating lubrication. Anyway, the vent blows at 40 degrees after a few minutes & then after I turn the fan down, it fluctuates between 30 to 40 degrees (confirmed with 2 different thermometers). Pressures are 35 to 40 PSI low & 230 to 280 PSI high. I thought the system was working great until I found this quote from a technician in an old thread (2002) in response to a poster who had stated that his conversion was blowing ice cold:
"Then its too cold....no system puts out air at 32F and is working normally, unless its a refrigeration unit..:) That would mean, the system is UNDERCHARGED....look at any refrigerant temp/pressure chart."
He was attacking the credibility of the original poster, who seemed knowledgeable but abrasive.
My understanding that overcharging with R-134A when converting was the most common error. Based on my pressures & temperature results, is my system undercharged? Is there something wrong with mys system to be blowing cold air. It seems to be working great. Thanks, Rich