Hi everyone! I am new to the Bonnie forum. I'm so gald I found a forum dedicated to Bonnevilles. They are great cars. I have owned 2. I currently own a 1992 Bonnie SE and need help with an issue I have had since I bought the car 2 years ago. My car is manual climate control (3 *****). The first issue the car has is that the air (hot or cold) will intermettently blow out the defrost and floor vents, no matter what setting you have it on. Usually after you drive the car between 10-20 minutes, the air flow will change to the correct setting (usually I use the center/side cabin vents) and blow out. Then if you turn the car off say to go into the store and come back out, after you crank it back it blows out the defrost vents again. I have lived with this problem, pretty well, but it gets annoying, especially when it'* summer and 100 degrees outside.
Second, the a/c has been doing something quirky. The summer before last, I had the system recharged with 134-a and all was great (except for the air blowing out the defrost vents at times) the air got cold and stayed cold. Then this past summer (200, the air didn't seem as cold, so I had it recharged. Now new issues have popped up. The a/c will get somewhat cold when you turn the air on for the first time after the car has been parked for a while (i.e. at work) but if you turn the car off for even a few minutes, and then turn the a/c back on, it'* not cold anymore. If you turn it off and try later, it will be cold again. Second, the air is now blowing out colder on the driver'* side than on the passenger side. this is puzzling. Lastly, few times the a/c is actually colder when the car is at idle than when you are driving down the road. I don't know what is causing all these problems. Any help or advicd would be greatly appreciated. I had 2 different mechanics look it, and really couldn't get a solid answer. One said my compressor might be going bad.
Thanks!

Toddster has a good handle on the HVAC stuff, he'* the guy to ask.

It sounds like your AC compressor is going bad or you have air in the system.

To me it sounds like you have a leak somewhere and your due for another recharge.
When the freon is down the compressor will act up as you described as well as the driver vents will also be cooler than passenger side due to low freon. And your car being cooler at idle is because the compressor doesn't have to keep up with the motor as hard as when its engaged.

So the long and short of it is you may need to recharge your system again and or have it leak tested and fixed so you can enjoy cold air all the time.

Do you notice if the A/C clutch is engaging off and on a lot of times when the car is idling?

The compressor seems to stay on all the time. The mechanic that told me my compressor might be going bad also did suggest that I might have air in the system. I did the re-charge myself last summer, so I might need to take it to a garage and have them vacuum the system and then recharge. I don't think it'* leaking, because I turned in on last week when we had some warm temps to see if it worked. It worked fine, (for the given temp at the time ) but as I know from experience it won't be cool enough to work when the weather heats up this summer. I just don't understand why the first time I turn it on it works, then if you turn the car off and turn the a/c back on again with a few minutes of time, it isn't cold anymore. You have to wait and let time elapse before it will cool again. This possibly could be related to air in the system??

There is a refrigerant pressure switch that will kick in and out when there is not enough freon in the system to hold it shut. I can see if there is air in the system the pressure switch is only working correctly when enough freon mixture is pressurizing the switch but when its diluted with air the switch will not work correctly.

There is also a pressure relief valve on the rear of the compressor that prevents the system from being damaged due to excessive pressure in
the high side of the system. If pressure increases to about 461-599 psi, the valve opens, venting refrigerant to the atmosphere. So if you had over pressurized your system and had let air into the system this would give reason for low freon but not low pressure.

So as you had already stated take it to a mechanic and have them vacuum dry the system and start from there....

Can you turn off the A/C to conform that the clutch disengages?

running for my life on posts. Todd.. for the window/floor issue, please look up vacuum can on firewall and the check valve/hose feeding it. Usually hose rots, valve may be bad and can might have crack.