Australian Car Repair Issues? Ask an Auto Mechanic for Answers ASAP
I am sorry that you have not been helped yet. I just came online and saw your question.
You dont mention if the battery is new or not. If not, even though it was disconnected, it may not be good, even it if is showing 12v. You need to also check amperage. Low amperage will cause same issues as low voltage. So first, we need to make sure there is a good battery in it both voltage and amperage wise.