Should a car start without altenator?

Given that the alternator doesn't produce any charge at cranking speed, yes.

Which earth wire do you mean? I've not come across a separately-earthed alternator or dynamo since Rolls-Royce stopped using them in the fifties, so do you mean the one from the battery to the body or the one from the engine to the body? Without the first one, it certainly won't start; without the second, it may do, but a hefty current finding its way back through odd paths (traditionally, mini choke cables or speedo cables) can lead to some interesting effects.

Astras have a separate earth lead from the engine to the alternator.

Well you've missed out on anthing made in the 80s or 90s by vauxhaul.

some vehicles may need the wires that normally bolt together on the charging post fixed together temporarily. some things like the rev counter may not work, but yes there is no major reason why you need an alternator to start and run a car. obviously it should not be for long as you probably have no fanbelt driving the water pump (depending on engine type)

when racing we never use an alternator, just total loss from the battery, mind you there are very few electrical loads, so a pair of batteries (24volt starting) last all day no problem.

mrcheerful

I don't recall Van Blanc (89 Astra diesel van) having one, but apart from that, I have, indeed missed out. Did they do it because the mounting bracket didn't give a good enough earth, or in pursuit of solving corrosion problems, which was Royce's reason?

It was simply because it was isolated by rubber mountings