986 clock flashing and lower dash lights won't turn off
 

I'm hoping someone can shine some light on this for me.

My 1999 986 2.5 was laid up for a period and suffered a flat battery. I guessed it wasn't a problem, fitted a new one and all was fine. Drove 30 mins, set radio, set clock etc and all worked. Parked it over night and the following day when I started the engine I notice the clock was flashing but it wouldn't let me set the time. After a couple of minutes the clock stops flashing and keeps time. As soon as the ignition is turned off the clock starts flashing again and after locking the car the lower 3 display panels stay lit.
Next I drove it for an hour and everything started working correctly. I could set time, it kept time and after locking the car the lights went off. I went into the garage a few days later and noticed that the dash lights were back on and I'm now back at square one.
Anyone have any ideas ? Do I need a new cluster?

One Possibility is your ignition switch could have given up the ghost - usually the electrical portion wears out. Not an expensive item as it is common with Audi and VW.
Part # 4A0 905 849 B