Few issues

Some advice required please.

My 2005 (05) fabia vrs has a few issues that I am trying to get to the bottom of.

ABS light is on, speedo doesn't work and the fuel gauge drops to zero when making a turn.

Also have an issue with the central locking. It will open with the key fob, also works to open rear doors with double click and boot and the car will then re lock it's self randomly. 

I have searched the forum and found a few possibilities, fuses earth's etc.

Any more advice would be appreciated. 

Thanks very much.