Audi S4 electrical problems, Any techs on here.

[Barry Ashcroft]

2006 S4 Cab, went to unlock it and no locking working, started the engine and after 10secs all the fans come on like it's in limp mode. No headlights, no electric Windows, turn the key off and remove and the radio remains on.
I've had to disconnect the battery.
Any pointers as to where I can start, pressing check on the dash says no faults.
Im going to get a friend with vag comm have a look.

Cheers.

[Easternlight]

Have you done the simple things like battery connections, checked the voltage?
Has it been standing for a while?
Could just be deep discharged, if so try trickle charging it.