electrical fault post rain

[tank1034]

i bought my berlingo van 3 months ago and its been brilliant 3 weeks ago had some rain wipers went intermitant and few days later rained heavy again and this time they stopped and lights remained on and no brake lights, had to get recovered
few days later it did start and then dash lights went crazy and lights remained on even when key was removed, i checked and removed tray next to windscreen to see if any leaks going into electrics round bsi thingy could not find anything
few days later i tried again all went crazy again managed to get started between nothing flashing lights beeping from radio handbrake light on etc 
took to garage they could not find where water coming in if that is problem they were poor to be fair did not charge as i said may as well get rid if they cant find anything they did not seen clued up on electrics to be fair
i have since tried re set bsi removed it removed wires from a unknown to me unit under bonet on passenger side and lights still remain on with no key in so have to remove battery lead 
i am hoping the experts on here can assist and its a simple fix as i cant afford anymore garage fees to be fair so any ideas worth a try apart from van heaven as thats my last resort as its been a great van 
thanks in advance hope this comes through as im new here

[dumdum]

What year is it? Guessing it's an 03-09 plate mk2... If try unplugging the comm2000 for a start, van won't start unless you start it and unplug the comm but you'll see what happens when it's out of the loop, it connects with bsi via canbus, as do the clocks and I've known comm units do all manner of silly things when they go tits up and it's an easy one to test...

Other than that I'd guess at bsi if I'm honest but it's French so it could be owt...

[Col]

Worth checking underbonnet fusebox for water ingress

[Tomcat3]

Clear the scuttle area and make sure the drain holes are clear. If they are blocked water builds up then runs down the loom into the bsi unit causing electrical issues like you are having. The holes run down and come out at the bottom of the wing by the door. Open the door and look at the wing edge and its probably full of leaves and mud clean out with a skewer then clear under the scuttle an make sure water runs away. Hopefully the bsi will dry out and a bsi reset will sort it out but water damage can corrode the contacts causing problems. There are threads on here covering this and taking apart the bsi to check/clean.

[tank1034]

sorry yes its 2006 and all gutters were clear no blocking holes will try rest of recommendations and go from there many thanks every little helps the annoying thing is spent 200 quid on serviced and 200 on new starter motor few weeks before ah well onwards and upwards