Screwy electriccery

[Bodger bedge]

Got a cerb 4.2 n its doing me ed in. Electric windows and door opening system stopped workin on both sides. Door locks failed first with windows failing minutes later! Boot release switch also not working. Tried the unplugging of little black boxes plus disconnected battery and reset system and alarm on re-powering up. Turning alarm on won't even power up windows to final closed position. Fuses OK.
Any such thing as a wiring diagram out there?
Any ideas what I can test for?
Please help before I pull final bits of hair out!!!

[kojak]

Is the battery ok?

[Bodger bedge]

New battery on a couple of months ago!
Thanks

[kojak]

You've done the little black box in the boot, so it cant be that.

Has it been charging up ok?

[Bodger bedge]

Charging ok. Every thing else works fine. Is there any simple tests that can be done on the little black box...ie check inputs and outputs? A wiring diagram would help here I guess....anyone have one?