2000 BMW 328i,airbag&seat belt light,cruise contrl,radio stopped working at same time

I have a BMW 328i year 2000. All of a sudden my radio went dead, cruise control doesn't work and the seat belt and airbag light in the instrument cluster stays on while I am driving. It all happened at once. I checked the fuse box under the glove compartment but they all are ok. I think one of the relay switches went bad. I need a diagram of the Relay switches which tells the function of each switch. One may control all. I opened the relay box under the hood but there is no diagram under the cover. I already called a couple of dealers and they told me that they have this info on the computer and I have to bring my car in and it will cost an arm and a leg. Does someone know the answer to this or is it some other issue with the problem? Bently manuals are expensive but it may have the diagram. Can I just get the diagram?

Thanks

AG

How old is your battery ?...

I just replaced it three weeks ago OEM

The first step I would take would be to double check your battery connections...Hopefully others will chime in with suggestions...

Try resetting your ECU and checking your battery.
Check your fuses as well.

Thanks for your help. This is helpful. The problem happened a week after I had my battery replaced. If battery connection is loose then how come other instruemnts are working?

Originally Posted by stox111us

Thanks for your help. This is helpful. The problem happened a week after I had my battery replaced. If battery connection is loose then how come other instruemnts are working?

Because it's getting power just but enough or to much.
You don't have a after market sound system by any chance do you?
with a after market amp?

This happened to me after taking a turn pretty hard the day after I replaced my battery. The connections were not on tight enough. I'd start looking there.

Thanks all. My Radio and CD changer is OEM, as a matter of fact everything in my car is OEM. I will check the battery conections again. since I had a new one installed and problem happened after that. I am also going to check the relays, as soon as I get a diagram. If there are any other suggestions, please let me know.