well today i was driving like you normally wood an last time i looked at the battery gage on my dash it was running aning about 14v were it shood be an it dropped to just above ten but the car still starts fine lights work didnt notice much dimming but the radio desided to turn off so im gussing the alternater might be on its way out but befor this was all happining i dont no if its got anything to do with it but i had steam coming from under the bonnet but the enging wasnt hot any ideas?

As you said, the alternator might be on the way out. There may still be enough charge in the battery to start the engine and run some accessories, but the more you drive the more likely the battery will lose it's charge. Before you change the alternator though, make sure the wires to the alternator are still in good condition and connected properly. Also check if the power steering pump isn't leaking fluid onto the alternator.

Not sure about the steam...you might have a leaking cooling system or something is burning off. Have a look around in the bay for any leaks.

I'd say you have a short somewhere. Check your starter wire (and/or amp cable) hasnt rubbed through to touch the chassis and that your battery positive terminal isn't touching the underside of the bonnet. If this is the case the steam was either battery gas or smoke and either way not a good thing, fix it before it catches fire!

get or buy a cheap multimeter $15 or less !! measure the voltage with engine off , then start engine and measure again should be in teh region of 14 to max 15 volts max.
if no change check connections on alternator and battery. if everything good there , replace alternator.
mark

check your alternator brushes and also check for power steering oil leak - the high pressure hose is right above the alternator and prone to leaking oil straight into the alternator

To true, i have lost count of how many falcons with alternators trashed by leaking oil int he term of my aprenticeship, funny thing is though most of the customers think you are having a lend of them when the tell them the alternator has failed due to oil leaking into it, they dont like it even more when you tell them the waranty on a brand new alternator will be voided if it fails and the fault is caused by oil leaking into it lol

sorry for the late reply thanks for ure help guys turns out it was the alternator had a crack in the frontseal an oil leaked into the brushes of the alternator an its fried lol