Battery Light on Dash - 2003 Symbol.

Returning home today after a few lovely days on the Isle of Wight, I noticed the battery light on the dash was flickering.
I then realised that as the light flickered there was a 'buzzing' beneath the drivers seat.  Knowing that there are couple of relays there near to the leisure battery, I initially suspected a fault with one of these so pulled over and unplugged both.  (I assumed that these are for the leisure battery charging).
The vehicle started ok and the battery light remained off, so we continued on our journey.  However, very shortly the light was flickering again and remained so until we reached home.  Strangely, it flickers much less at slower speeds
Does anyone have any ideas:
As it it does not appear to be the relays I am thinking alternator, but the van has only done 37,000 miles.  My other thought was some kind of earthing issue ??
Thanks.

Alternator belt need tightening?

Hi  


The battery light on is a pretty good indication that the alternator output is low or non existent. It's certainly worth checking the belt but if it's loose it's normally accompanied by a tell tale loud sequel! I have certainly known alternators fail at around 40,000 miles.

I'm not absolutely sure about your particular van but the split charge relay was often driven from the alternator warning lamp connection. That could explain the chattering relay.

Luckily it's not difficult to do a rough check on the alternator. Just connect a voltmeter across the starter battery, start the engine and make sure the battery voltage goes up to around the 14V mark.

It's normally a good idea to check the voltage output on load (the lights will do initially) but the indicator light normally indicates a go or no-go condition so you probably won't need to.

Brod

Thanks Paul and Brod.
I will check the belt tomorrow as a starting point, but I haven't heard any squealing.

If that is OK, I'll move on to testing the voltage.

Thanks.
Carver

As a round up on this, I have now resolved the issue, but thought it worth posting for other Boxer owners of a similar age. 
I replaced the auxiliary belt tensioner as the existing one seemed less 'springy' than it should, although this did not cure the problem.  However, when looking under the van to inspect the alternator I spotted a tiny drip of diesel on the base of the high pressure pump.  After a little advice I decided to have the pump refurbished / repaired by a long standing firm with extensive knowledge of these Bosch systems.  He told me that he sees many of these pumps and that leaking is an issue.
As the timing belt needs to be removed to replace the diesel pump I decided to have it changed at the same time, together with the pulleys and a new water pump. 
So far so good, but then still needed to sort the alternator problem.  
I took the van to another specialist (starters and alternators) who spotted that although the shield fitted had done it's job in preventing diesel from dropping directly onto the alternator, some had found its way onto the cable and run along and in that way !
Once removed, the problem inside was as he had predicted.  The diesel causes an electro/chemical reaction and although the van hasnt done excessive millage, the slip ring was worn away almost completely by the brushes.
He told me that the slip ring becomes elliptical hence why the light flickers.
Anyway, new alternator fitted and after a weekend away, so far so good.
Sorry for the long (and boring) post but may help someone else with similar problem / symptoms.
I just need to get over the cost now 
Regards, 
Carver