V8735i

Whilst driving my 1998 735i 100k I find the following occurs at random times. Anyone else had this and/or know ho to fix please ? 1st thing no radio, no on board computer, no horn, no cruise control, slight lose of power steering, 2nd thing all of the above plus asc light and abs light. 3rd thing as 1st thing with addition of air bag light glowing. 4th thing everything back however air bag is still glowing. Bugging me and wondering what's going wrong. Thanks for reading please help