Hi All,i have a 2004 fiat doblo 1.3 multijet diesel and the problem i have that if i select reverse or put my foot on the brake the engine will cut out and i lise all electrics including the dash lights,i have unplugged the reverse light so that problem has stopped if i unplug the rear lights on both sides it to stops the problem,any ideas ???? is it a possible body control module fault ?/Thanks for any help in advance

It could be a control module fault, but best to start with the basics.

Remove the whole lamp unit and check/clean all the connections. All the bulb holders and connectors, plus the wiring plug and special attention to the earth connection. Try to trace the earth wire to the body connection point. It is possible that the lamp has lost its earth and any bulb fed is feeding back along any and every other wire and giving the control module indigestion. Also worth checking battery and engine bay earth connections.

Have a look at past threads. There have been numerous reports of the Doblo main chassis earth strap corroding internally and causing all sorts of gremlins. The lead usually looks ok but isn't inside.

Also check the brake light bulb is correct, has been known for a dual filament brake and tail light to be replaced with a single filament and short the electrics which would explain the lights going out but also you would expect a fuse to blow as well but then if the fuse has been replaced with a nail well could be very dangerous.