grand marquis 2006 blower in a/c and heat won't quit blowing
blower won't quit blowing on a/c and heater
I had the same problem a few days after I bought my 2006 Grand Marquis (used) in late 2006. It turned out to be just a bad resistor somewhere in the blower control. The dealer fixed it and it's been fine ever since. Sorry I don't have a DIY solution.