My a/c only sends air through the defrost and floor ducts. Doesn’t really cool much for less than 20 minutes run time. Since I deliver newspapers to commercial stops, I rarely run that long between stops, and would like to have better cooling. Any suggestions?
When properly functioning, the AC in a Grand Marquis is one of the best available. It should pump out plenty of cold air whenever you want it.
I think you need to visit an independent automotive AC shop and have the multiple problems with your AC repaired. They can fix the air flow problem and the lack of cooling problem.
What year Marquis? I would suggest putting your back up information in the main message area and not the tag area. A lot of people like me, miss that tag area. Consider it a good place to put key words so someone searching can find the tread.
I suspect you may have a blend door problem. It may be a vacuum issue. That would explain why you are not getting the air out the other areas.
Also it sounds like you may have a low charge of refrigerant. I strongly suggest you have someone with the experience and proper tools to measure it and if necessary hunt down the leak if it is low as a properly operating AC unit should loose very very little refrigerant.