Resistors

[Krueger]

I have a '77 300D that I cannot start. A few days ago the glow light indicator did not come on and the car would not start. After checking the plugs I noticed the 1st one was completely fried (the core completely melted). I also noticed that the wire and connector to the 1st resistor was completely blown off. I proceeded to change all five plugs and the fuse, connected the resistor, however the glow light still will not come on and the car will not start.

Being an amateur, what part do the resistors play? Is it possible that this is what keeps the car from starting? I have not seen any information in the forums about this topic - it's always about the plugs and the relay. Are the resistors connected with the glow circuit? Any info will be greatly appreciated so I can get her back up and running.