When I turn the key on my 2004 XJ8 to start the car, headlights and dash lights start flashing and making a clicking sound, but won’t start. The car was working fine before I disconnected the battery for about 90 minutes while I was doing some work with the steering wheel and disconnected the airbag. I reconnected the airbag then buttoned everything up. When I reconnected the battery everything seemed fine when I turned the key to the on position. It asked me for my radio code and to apply the handbrake as normal, but when I went to turn the key to start the car everything started flashing and making a clicking sound. The car just won’t start. The battery is only 10 months old and everything was fine before I disconnected it. The connections are solid just like before. anybody experience this? What could be wrong?

 

Try one of your other ignition keys in the column lock?

 

Yes, thanks. I just tried it and same thing. Battery is fairly new too. It's showing a DSC fault sometimes as well as those lights flashing with the clicking sounds. I can't imagine how disconnecting the battery, then re-connecting 90 minutes later could do this.

 

Battery might be fairly new, but is it fully charged?, sounds like low battery to me.
Double check the battery connections too, maybe terminals are not clean or not fully tight, or you could havedamaged the wiring when you disconected the battery cables, seen it happen on earth wires, they can be quite stiff and can be damaged moving them.

 

SOLVED! It was a bad battery at only 8 months old. FYI apparently no one at the auto parts stores knew about the venting tube to the outside. Make sure you know to hook your battery up to that venting tube to keep the battery gas or whatever it is out of your cabin since the battery is in the trunk. Then use the plug to seal the whole on the other side since there are 2 holes to choose from depending on which way your battery goes in.