flashing battery warning light

Hi. The battery warning light on the dashboard is flashing when driving, there is no problem starting the vehicle  but the leisure battery is flat. One for the relays is chattering, when I removed the the relays the battery warning light still flashes.
I connected the electrical supply to the van to charge up the leisure battery after 3hours it was still flat, any ideas on the fault please.
Alan

I know it's a bit late to say this, but it's a really bad idea to run the vehicle engine when the leisure battery is completely flat. The problem is that when you start the engine, the split charge relay connects the fully charged (and being charged by the alternator) engine battery to the flat leisure battery, and much too much current flows between the two - if the wire were thick enough between the two you would perhaps get 50 Amps or more flowing.

Under those circumstances, something usually breaks. If you're lucky it will be the fuse on the split charge circuit. If you're not it can blow other fuses (in your case possibly the one immediately next to the leisure battery) or it can burn out other components - such as the split charge relay.

Realistically all you can do is look for and find all of the fuses - which is never easy, because A/S put them in different places in their conversions, and two similar vehicles will hardly ever be exactly the same. Then have the leisure battery tested to see if it's dead. If it is, replace it, and charge it fully before installing. If it's Ok, recharge it with a separate battery charger and then reconnect it, then replace any blown fuses.

Unfortunately a flashing light on the dash is likely to mean something has also failed in the vehicle's charge circuit (whether cause or effect of the other problems is unknown). Check the base vehicle's Owner's Manual to find the exact meaning and get it fixed - if it's like a T5 then there's a separate fuse (fitted by the base vehicle maker at the factory) for alternator output.

Hi Almar,
We have a 2003 Symbol (I think the same base vehicle as yours).
Shortly after acquiring the van about 2 years ago our van did exactly the same and once I had discovered the problem the symptoms made sense.

It turned out that it was the alternator at fault.  Specifically the slip ring that distributes the power output via spring loaded carbon brushes.  On ours the copper slip ring had worn through on one side which created a 'dead spot', acting like an on-off switch.  

The relay that is chattering will be the one that disconnects the habitation (12v) circuitry when the engine is running. As the power from the alternator comes and goes the relay thinks that the ignition is being switched on and off, hence the rapid clicking.

On our own van, I was initially a little skeptical of this diagnosis from the auto electrician, as the Symbol had done less than 40,000 miles (much less than than would be expected for the life of a factory fitted alternator). However, in our case a tiny diesel leak from the diesel pump had found its way into the alternator via the connecting lead and had led to a chemical reaction causing the copper slip ring to be eroded.  The auto electrician said he had seen the same issue many times before.

It could simply be that your van has a lot more miles on the clock and the alternator has simply worn out.

I hope that this is the case because in our case we also had to have the diesel pump removed and repaired. - An expensive job.

I'm not sure if the flat leisure battery could be connected ??

I hope this helps,

Carver

Hi Thanks a lot I will let you know how I go on

Thanks I will let you know how I went on.

Hi. flashing light on my symbol dash board sorted, it was down to the cover plate over the alternator. The feed cable from the alternator was touching the cover plate which had cut trough insulation and the wire to dash board was nearly cut trough, I reinsulated the main cable and repaired the wire to the dash board I also replaced the relays next to the leisure battery. 
Everything working fine.
Regards Alan

Glad that you got it sorted and not too expensive a repair by the sound of it.

Regards,

Carver