Starter motor, earth strap.that two things i acn think off.
I had a battery once that did this. Seemed to be a bad connection inside. When it was OK it would crank the engine with gusto and then it get the hump and would not go at all. I doubt if it is the starter otherwise the dash lights would not go out. A meter directly on the battery terminals should show what is going on. I'd suspect the earth strap first. Bob
Hi, Could well be a broken element or connection inside as well. According to my usual mechanic, it's pretty usual indeed (less lead inside, weight and cost reduction too). Right method for diagnostics to me. The voltage, in case of a broken element, is almost OK (12,xx V) when engine is off, and drops under 10V, I mean far under 10V (perhaps just 8) under start. The earth lead is an idea too... We should be careful with these things more often indeed, as it's almost nothing to do but hangs you on the side of the road anyway. Regards,
