Hi and thanks to anyone who replies

 

If I wait for the Glow Plug icon to go out, the car starts ok. I've had the battery checked and it's fine. However, if I turn the key before the Glow Plug light goes out the car won't start. Then when I turn the key and try again, there isn't enough umph in the battery to turn the engine over. Any pointers please? Suggests to me the battery is not being charged much as it runs - alternator issue maybe?

@keenonfabias - Start by using a multimeter to check voltage over the battery engine off and running. Expect 12v off, and 14.4 running.

Does the battery light illuminate with the ignition on without the engine running?

just wait  that's what it's for,    you're getting full load of the plugs (huge)  + starting current( huge)  + power steering load(which can't be avoided) ,   all at once  and the battery (how old/when last charged ( externally?)) + cold weather(reduced battery efficiency)  + thick oil,    a bit of mechanical sympathy would help a lot----"hear endeth the sermon",   I 've used up my bracket quotient

I suspect the battery but if it really isn't the battery you must have a bad connection somewhere and the starter can't get the current it needs.

First thing to do is check the answer to TMB's question but just a note on a previous comment - the power steering takes vitually no current if the steering wheel isn't being turned, like 3 amps.

keen on- those of us who cut our teeth on the first generation of derv vehicles were taught to let the light go out. ( In my first van, pre first generation, , there was no light- you light a ciggie, pressed the button and waited till you'd finished ciggie, before starting) .The light is there to tell you that glow plugs have done thir job and you can now start engine.