My alternator light goes on when I start the car after its been sitting over night. The light goes off as soon I start to drive though. I checked the belts, they flex no more than 5mm and they look alright but I don't know when they were changed last. I should not have to worry about getting stuck somewhere unless the alternator light is on all the time right? and... is this a sign of the alternator being on its way out?

Sounds like brushes. I noticed mine doing that but I put off the repair. A week later it died in the left turn lane at a red light in city traffic. With the wife in the car. AAA aggravation, towed the car, etc. Lots of fun.
--
1986 Volvo 245

Yes brushes, or the whole voltage regulator if you don't want to solder the brushes in. But do it soon, shortly it will stop working altogether.
Suggest you get a cheap voltmeter, then you can check your charge voltage at the battery.
--
84 242Ti IPD bars&springs, 89 745 16v M46 IPD bars, 89 744 16v M46 IPD bars, 93 945 Turbo AW71, 91 245SE AW70 IPD bars, 93 245 CLassic M47

It sounds like a set of brushes might just fix what ails it.

Regards,

Paul

Does this explain why the key-in-the-ignition-ping and what I think you call dome light been acting funny recently even if the car is tuned off? So when I look at this Bosch Vregulator on internet it seems that the brushes are in the regulator, am I right? Do I have to take the alternator out to get the regulator off? And if its the origninal regulator maybe I should just get a new one, I meen does the rest of the electronics go bad in them?

Before you buy a new regulator and/or brushes, you can inspect yours for wear and see if they are worn out:

If the brushes show uniform wear, they are not worn out yet. If they have different scratch patterns across them, they're going, going...

The ignition switch can wear out, and (even if it's not worn out) a heavy set of keys can make it stick in the start position, or inbetween positions. I've had it happen where my car gets stuck with the starter engaged because of key position - the radio, fan, and dome lights don't work because there's a path of much less resistance through the starter.

Good Luck,
Will

If I understand you right you meen that if they're not worn I should get a new regulator or maybe even a new alternator?

I should've explained the ping and dome light. What happens is that when I have the door open and start the car the ping sounds kind of like when cop cars in films crash and their sirens dies out. The dome light after I've closed the door it start to flicker, get weaker and then goes off, a little bit earlier then usual I think.

Those sound like symptoms of low system voltage. Your battery is not being adequately charged, and things that rely on 12 or more volts can act funny when operated at a lower voltage. Get your alternator/charging system squared away first, and see if those symptoms disappear.
--
In God We Trust. Everyone else, keep your hands where I can see them.