There are loads more on reader and dash but struggling to upload them

 

Let's start with the questions that everyone is asked when there is an electrical problem on an XK.

How old is your battery?
Has it been checked out?
Have you had the car on a battery tender like a CTek?
Do you know what state the alarm (locking) sounder battery is in?

 

The battery was new. Problem started a few days later. Since then I must admit the car has been stood a few months and the battery went flat. I charged it overnight and it started straight up. Left it running. Then went back to it 5 minutes later and all the faults returned. Then 5 minutes later it started again. It seems very intermittent. 1 minute it starts, then it doesn't. I don't know how to check alarm sounder battery

 

Your symptoms all point to a bad battery - the fact that it was allowed to go fully flat will not have done the new battery any favours.

As has been given as advice many times on this and other forum, these cars are particularly susceptible to a poor battery, and it is not uncommon for a new battery to be faulty from the get go.

The battery's ability to start the car is no longer the definitive proof that the battery is good, the modules around the car that comprise "The Brain" are extremely sensitive to voltage fluctuations, which can come from a poor battery or a failing alternator. I would suggest you find a good auto electrician and have the car fully tested, including the fitting of another replacement battery - at least temporarily to check the systems.

Scot Amb