Glow Plug Timer for a BX25D???

[William1]

I turn to glow plug, one-one thousand, two-one thousand .... up to ten and crank.

I was wondering... is there an add-on timer and light? Ideally a setup that is based on resistance change (as the glow plug heats, its resistance drops, a normal electronic function) Vs actual time.
It'd really be nice if you could just turn the key to crank and once the glow plugs were up to temperature, a relay clicked and it just cranked.
Thoughts?

 

[GreensvilleJay]

Well the concept is good, modern($$) tractors have a similar system. Electronically, you need about $50 worth of parts, computer, relays ,case.....

 

[Hugo Habicht]

Normally the glow plug time is determined from the ambient temperature, or better, the engine temperature. In my tractor it is integrated in what is called "combination box" but I am pretty sure a lot of older tractors had a separate glow plug timer.

P.s.: as far as I know most heating elements increase their resistance with temperature. I am not aware that there are glow plug systems that take the resistance to obtain glow time, but if it does exist, I'd like to know about it.