1972 142s ok so I put a new battery in my 142s which has been sitting for about 5years, it turned over about 5 times then the power cut out, now if I can get it to read the power it just clicks the cuts out? any ideas? checked the connection from the starter to the power battery all good and the neg is securely bolted to the battery tray the only question is the black cable which goes from the positive to a relay on the side of the car?
thanks
Justin

It's been a while, but I think the relay on the side is for the headlights.

Check the connections on the starter motor, and you can also measure for a voltage drop across connections when turning the engine over (i.e. probe on cable strands and on bolt at each connection and see where you have a large voltage drop).

My S40 had a similar issue but regarding not charging properly which no one could find, and I've discovered it was a connector crimp between the alternator and the starter motor that was not absolutely perfect. It takes very little to cause a voltage drop. I've fixed the crimp and a few years later the issue never came back again.

Have you checked battery voltage?.Sounds low to me. 12.8v is good 12.2v is flat. Dont use a jump battery or you will end up with two half flat ones.