Hey guys, Scooby is runny lovely ATM however occasionally when I come to start it it struggles to start. I can hear the fuel pump prime but it just won't crank. Any ideas?

Crank sensor maybe ?

It won't even turn over?

All the lights come on, but they dim as I try and crank it. Could it be as simple as a poorly charged battery? The idiot who had it previously has put all led lights in the cabin. Not sure how they have been wired

Could be battery or starter motor starting to stick.

If the lights dim it suggest the starter is drawing the power but not turning. I had the exact same issue on an old astra.