A/C works but only cold air from 1 vent??

[NCVaul2]

"Hi,
I have a 1990 Accord Ex with 366K on it. Last year the a/c became inadequate and blew only warm air. I had the refrigerant changed over to R14a (or whatever the new initials are for the new "freon") and my mechanic said the compressor seemed to be fine & found no leaks in the system. However, the problem remained in that the air was only cold on 1 vent. The passenger's vent (by the passenger's side door) is the proper temp (like 40ish degrees) but the by the time the air is piped to the drivers side vent its only like 70ish degrees. The ones in the middle seem to run about 60ish degrees. My mechanic's theory is that there is something wrong in the heater box--perhaps there is a flap or two that is not opening properly to pipe the cold air to the other side of the car. Equally ironic is that as long as the car is moving at highway speeds (say 55mph and up), the cold air flows okay ( I have all vents shut off except the one by the drivers door and he one immediately right of the instrument cluster to keep me cool---I am normally the only one in the car) until I have to stop at say a stoplight. More irony is the air is cold for all vents for just a few minutes when I first crank the car and its idling but this stops shortly after the car warms up.

My question is why is the air cold only on 1 vent (the passenger vent is the port of entry for a/c too --interior of glove box stays cold when a/c is on) but why does the air seem intermittent especially when I stop the car yet is somewhat okay even on the driver's side at highway speeds only. We also manually turned the valve for hot water that goes to the heater coil thus there's no chance the air is being mixed with heat. Any ideas?

Thanks

Vaul

[ProMan]

I am not sure why it's cold on one vent. Maybe have something to do with the design.

Anyway, my 92 Accord had this problem 2 years ago. I looked at the glass window on the receiver/dryer and it had a lot creamy bubbles in it. I recharged the freon and the problem resolved.

[NCVaul2]

Originally Posted by ProMan

I am not sure why it's cold on one vent. Maybe have something to do with the design.

Anyway, my 92 Accord had this problem 2 years ago. I looked at the glass window on the receiver/dryer and it had a lot creamy bubbles in it. I recharged the freon and the problem resolved.

************************************************** ****
I had the freon recharged and changed over which somehwhat helped the initial problem but I cannot understand why COLD air in the main vent where a/c enters the vent system and cool air everywhere else. Equally, I was told that once you change the system over to the "new" freon (R14a or whatever its called), the sightglass on the rec/dryer is not accurate for determining whether or not you need more freon. I forget how much he put in it, but he was afraid to add more for fear of damaging the system and he didn't have his gauges with him to see hwo much pressure was on the "high" side. Does anyone know how the flaps in the heater box stay open? Are they pressure regulated or is there a motor that keeps constant pressure on them? Any ideas???