Transit doors not unlocking

[Ciarán81]

I have a 2010 reg ford transit 115 T350. I had the sliding door handle replaced earlier in the week and then the following day all doors in the van are locked and won't unlock bar the driver door as you can use the key on it. When you press the lock / unlock button on the key there is no response from the central locking now either. What could be causing the problem and how do I get the doors open again as I'm badly stuck to get them open?

[Altransit]

The first port of call is to check that your front (aux) battery is not flat. Having the side door open for a time whilst you worked on it could have killed an ailing battery

[Ciarán81]

It turns out this model transit has three separate fuse boxes. One is under the hood and was checked and no issues there. However the mechanic I eventually found that was able to fix it knew that there were two more. There is one directly behind the glovebox and the key one further in past that one. There was a blown fuse in the second box and this was the issue. Glad to be sorted and hope this helps others.