I've had since buying my GT a few years back constant issues with both windows, driver's is worse where you have to do the reset by holding down the window switch for 10 seconds. All but twice it fixed it. Happened on the odd occasion with the nearside window too. One time I opened the door and the window wound down by itself. I wound it up but as soon as it hit the top it went down halfway. After several of the resets and a door open/close it worked.
The Friday before Christmas me and my girlfriend went to see friends near Chester. They have a long drive to/from the house onto the road. I wound down my driver window becuase it's easier to reverse for me that way and it stayed there. Like the OP it bleeped to go up but would not. I tried the 10s window hold and nowt. Off the ignition, open and closed the door, zilch, nothing.
We drove home in the partial wet and cold with the stupid window down. I got home late about 12:30am and just taped a plastic (black to match the paint) bag to the window. In the morning I disconnected the battery for a good half hour, zilch, zero, nowt. I'd opened the door again several times. No window drop, nothing.
I had to take my GF and her son to see her other son so I dropped them off near my Mum's and as she has a car port I went there and took the door card/trim off, the window/mirror switch off and the door control unit at the bottom right. I noticed that clicked when putting the window down (it was if you recall stuck down at that time) but when pulled up it did nothing. I removed them both and pulled the polystyrene sheet off the door (that will need sticking back properly). I worked out there is, on mine two thicker wires to the motor, one orange and one grey. I took a chance (was pretty ****ed off with the thing now anyway) and first attempt tried to wind it into the floor
. Swapped round the clips and bingo she wound up.
I spoke to Gaz on here and he put me onto Gus at Alfatune in St Helens. Very helpful, he was to arrange for me to come in and try the window control unit and a switch. Unfortunately Gus does not have a GT window switch, only 147's and they are not compatible. Between us, Mangos part's guy and AutoLusso it seems the window switch is most likely the problem. Anyway I ordered one off AutoLusso (£127.50) via eBay. It still hasn't arrived yet but I expect it anytime soon. If that does not work I'll have to buy the control unit at about £50. These are used parts not new. If after that the window still does not work it will be the body control unit. This does not often fail and I'm unlucky if it has but it is about £400+ to buy. At that point I will take a live from the battery and rig up a relay, punch a hole in the door card and put my own switch in.
I will keep you informed as to my progress. I should also mention that currently the inside door card is still off. I attached the window control unit and taped the window switch to the polystyrene cover so I can operate the passenger window, the heated mirror and the boot release. Been using the Mafia kidnapped boot release string to open the hatch. A right royal pain.
What I have not done since taping that lot on is try the window again. I can't be bothered to have to wind it up with a 12v supply if it winds down, which I think it may. I will try that when the new switch arrives.