240 help with cruise control, central lock, ardic heater, alarm system
 

i have these great accessories on my 240, but they dont work so well.
first, the cruise control. never has worked while ive had the car, what could be wrong and where to start looking.
second, central locking system. sometimes works, sometimes not. now its completely dead. whats wrong with it?
third, the ardic heater. it works for a couple of minutes and then it turns off. i dont know if you guys have this heater in U.S, its more common in cold countries.
finally the alarm system, should i have a remote or something for it? now the alarm system goes on only from the back roors, trunk or the hood. and also goes off only from these spots. do i have to get it programmed or what?