1988 Deville - Blower, Power Antenna, Headlights & Service Codes

My first post so I thought I'd get it all on the table....

1st: My ventilation system has not been able to divert the air anywhere but on the floor. I need it to at least defrost the window for now.
I assume this is a vacuum issue?

2nd: My heating system has started to act up as it has started to get cold. It kicks the blower on when it feels like it. This can happen normally, when the car heats up. Or after a 45 minute drive, then it kicks on. And sometimes not at all which was the case yesterday during the 7 degree weather we had here.
Is there a thermostat which activates upon the engine reaching a certain temperature?

3rd: My power antenna is dead. I'm sure this is a surprise :lol: . I have had 2 of them replaced in the past.
Is there some trick to removing them?
Is there a way to get it in the full up position and leave it there?

4th: I have the Sentry system for the lights. It worked fine up until recently. Now the parking lights work fine, but the headlights don't come on anymore. I have to manually switch them on.
Is there a relay somewhere which controls the headlights?

5th: Service Codes I have displayed:
E30 - ISC Circuit Problem - What does this mean?
F46 - F47 - A/C issue (I have a bad leak at the A/C unit)
F49 - High Temp Clutch Disengage - Should I worry about this?

These 2 codes displayed also but couldn't find info on them:
FF46?
FF47?

If any of you gurus out there can help with the heater/blower issue at least, please do. It is getting hard to drive with a layer of frost on my windshield! :banghead:

Thanks in advance,
Jeff

As to getting it to the full up position, just pull it with pliers and leave it all the way up, it'll stay trust me, thats how my 1988 Sedan Deville is now, cuz the sumbitch kept runnin, I cut the wires, kept runnin battery dead, the rest, well I am tired, so I cant think straight, so well, there was a heater core issue, do a search for my user name, then find all posts, its in there