Car wont start, dash lights fading.
I have a pre facelift 2000 Audi S3, that has just developed a starting problem. I've had no problems with the car over the last year until now. Two days ago it became I found that it did not start on the first turn of the key and put this down to not being driven in the previous three weeks. I drove it for 10 minutes or so and parked up, 20 minutes later the car took 5 minutes to start. The following day the same problem but over 5 minutes to start. The battery seems strong when it goes to turn the car over and even replaced the battery as thought it may be dodgy but still the same problem. The dash lights are faint (air bag, battery, hand brake) and dim on and off every three seconds while the ignition is turned on, while the clock and odometer are remaining bright. The DIS lights up properly but takes 3 or 4 seconds to do so unlike before. The only problem I've had with the car is the rear brake lights have stopped working (probably brake switch) and got an error for this on my DIS. Which is the reason I haven't driven it in three weeks. I tried running the VagCom but it seems that it cant communicate properly with the car with this problem.
Any help would be greatly appreciated.