2001 Holden Ute vu ss Ute.

After not using the ute for 5 weeks as I was on holidays, went to start it but it took about 7 or 8 seconds to turn over and eventually come to life. Took it for a good spin to try top up the battery but no good so got a new battery for it. All went well for a couple of days until I took it to a carwash, turned it off to get coins and then it wouldnt start when I got back. After 10 mins and 20 + attempts it started. Since then it has had a mind of its own and started when it felt like it. I had a look at the ignition switch, fine. Starter motor and solenoid, fine. It has been laid up for a week now and any help would be greatly appreciated.

cheers