Caprice classic 1984 electrical fault can anyone help?

For the past few weeks my car has struggled to start, its always started in the end but if it doesnt catch it wont start straight away if i turn the key straight after. After a few spasum attacks with lights on my way home last night i tried to to start it this morning and it wouldnt catch, then the aircon, radio and electric windows wouldnt work and there was also a faint burning smell from the engine bay, now no hazzards or anything else but the head lights which are just as strong as usual so not the battery, its not turning over at all now so not the fuel pump, surely its not all on the same fuse so it cant be that when i push the key in the barrel with the door open it beeps so it seems like the barrel is working but no ignition, could this be the ignition coil or other thank you