Just acquired 1997 Golf GL TDI 101,000 miles and great condition. No handbook. Glow plug light does not come on at ignition but car starts and runs fine. Realise it could be the dashboard light and also read with some diesels as open drivers door automatic warm up so plugs don't come on. Any ideas.

What is normal runnig temperature maybe themastat gone and sticking open. seems to run cool and only gets up slightly above 1/3rd of gauge.
Any help appreciated. How difficult to change if try yourself?

Thanks everyone.