RX350 - Alarm and clicking noise

[tannee]

Hi All

I have a 2008 RX350.

All is running well until a few nights ago.

When i shut off the engine and pull the key out i hear a constant clicking sound. I dont really know where its coming from but i can kind of pin point it maybe to the windows or door i'm not too sure. I also notice the interior light flickering to the same pattern as the clicking noise.

That's the first problem and i'm not sure if its associated with the second problem.

Second problem - in the middle of the night the alarm goes off! Its the alarm without the horn noise. For some reason i cant switch it off with the fob key. No matter what i do i cant switch it off. So it goes on for about 20 seconds and stops. I just leave the car unlocked after that and it doesnt come back. The alarm noise is coming from the boot....

Any ideas?

I suspect it could be a dying car battery? I'm not expert so just hoping someone could help.

Cheers

 

[tannee]

Bump.

Now the navigation screen flickers. Blacks out then the lexus emblem appears then switches back on itself. 

Help please....alternator? Battery? Seems to be all related to one thing?