Hi all got a really good for you all
2003 fiat Ducato 2.8 guy jump started it and hit the live against the body and shorted it then the van cut out.
Now the van starts and runs but when you switch the light on cuts out and will not restart and Windows and stuff go dead
Have checked all fuse and relays and replaced all bulbs on the van
If the headlights are unplugged you can operate the light switch and the van keeps running ...plug a headlight in and cuts out again what's people's thoughts on this one
Thanks

A basic check (if you haven't done it already) is to measure battery voltage when this is occurring.

If the voltage drops considerably when you switch the headlamps on, the stop solenoid on the pump may be also dropping out. If so you will then have to investigate why the voltage is dropping which will be fun (unless of course the battery is even more b*******d than before by being shorted out!)