I recently bought and XJ40 and it ran great but this morning the wife went out to start it and its making a buzzing noise as if the headlights are on but they're not and the dash lights dont come on and the car doesnt turnover. Any help would be appreciated, Im a good mechanic but not a great at diagnosing. And I have searched I promise!

 

Do the headlights work OK, ie is your battery dead. These cars don't buzz, they have all sorts of different beeps/chimes.

Is the noise a rapid bip,bip,bip,bip,bip. If so try cycling the gear shifter from Park to Neutral and back to Park. It may be that the car 'thinks' it is not out of gear with a bad park switch.

You might also try to start in Neutral to see if this helps.

 

The buzz may well be the starter solenoid chattering due to bad battery/low battery charge.

 

I feel like tard now, I actually figured out this morning that the automatic seat belt actually jammed and when you open the door it doesnt go forward so you can get out but you can hear the motor or something forcing itself trying to move the seatbelt. So my consensus is that it drained the battery from trying to move the seatbelt and I put my jumper box on it and it still didnt do anything. I took the battery out and dropped it off at the "zone" to have it charged and viola! Back to normal, so I need to get the seatbelt crap fixed now. Thanks Translator

 

Don't feel too bad about it. We don't have those 'Attack Type' belts, so it would most probably have never crossed my mind that a seat belt could flatten a battery.

Hope that's all it was.