Welcome to the Two-Sixties! Your problem is more than likely down to water in or around the BCU I believe it's behind the glove box. Check the carpets in that area. If there wet there's a good chance you've found the problem. If there dry you may have just caught it. Either way the guys are right in saying it may be an idea to join the forum and unlock lots of great info on the cars.
How long have you had the car?
Regards
Nigel Baines
MG ZT 385 SE Starlight Silver Reg 29 Sep 04 Vin No 496 `Roush Supercharger fitted 07 Feb 11`
Ah, that explains it. So you aren't a 260 owner but are asking for a friend. Why doesn't he/she join up?
Nich.
Nicholas John Peter Tinker - # 484
Manufactured on Tuesday 27th April 2004 @ 12.17.47.
Commission Number: 24468.
Brochure Model: M3 Tourer 4.6 V8 260PS.
Specification Code: L01B.
CICode: D1511.
Trim Level: TL8.9 (M3).
65th ZT-T 260SE to be made out of 115.
11th ZT-T 260 SE in Pearl Black (PBT) out of 23 produced. Manufactured in the UK by MG Rover Group Ltd.