I'm unfamiliar with the term "glow eye". If this is the heated wire indicator that the glow plugs have power then yes, it is in series with the glow plugs. They will work fine if you short across the indicator but you'll have no indication they have power. Going without the "glow eye" will shorten the life of the glow plugs as they are not a twelve volt device. They actually want 10.5 volts as a general rule - depending on brand and model of course. When the glow plugs do burn out you will have no indication of it, other than the tractor will become really hard to start. Feel free to ask me how I know. By the way, the series glow resistor may not be burnt out, it may just have really oxidized contacts.