[Vwdiesel] Glow plug circuit questions

[Tony and Lillie]

I have a few questions about the specifics of the glow plug circuit. Patient is a 1982 VW Jetta 2-door non-turbo. It currently has a push botton hooked to a ford starter solonoid that opperates the glow plugs. I want to put it back to original.

1. Where is the original glow plug relay located?
2. What senses the temperature for the glow plugs to turn on, and where is it located?
3. What determines the length of the glow plug cycle, and where is it located?

I'm basically rewiring most of the car, as the wiring is pretty bad in it. So, I figured I'd take the oppertunity to fix this as well.

Thanks in advance,
Tony Hoffman