Glow plugs lamp- does it go out?

We are making progress with the old 1984 S3! Various niggles now fixed- I can now lock the back door and the heater works again (connection behind switch was loose). Latest query is on the glow plug or cold start warning light. Is it supposed to go out when the plugs are up to temp?I held mine for about a minute and it was still on. Also, any ideas why it is supposed top be a 6v bulb (according to the handbook). I have a 12v one in there currently. It seems to work.

Joe

It doesn't go out because you're the one keeping them on!
Warm them for a few seconds, turn the key into the starter position and the light will go out immediately.

Seconded...I used to count to 10 then crank...let the key go and the light should go out,

Leaving then on that long could burn them out...especially if they are the older curly wire tip type.

Nick.

Thought it only went out if you had the older wired in series type so the resistance changed as they got hotter.
If the plugs are in parallel, then it's just on or off. In that case case the bulb does matter.

From memory of mine....I think the lamp glowed slighty brighter the longer they where on with the old type.