Glow plug issue

[Do a lot]

Can a relay keep glow plug from coming on 1725 new holland tractor

 

[Roadworthy]

I don't understand the question. If your glow plugs are fed via a relay and the relay doesn't activate that can certainly prevent glow plug operation. On the other hand if you're asking whether you can add a relay to prevent their operation that can be done, too.

 

[thclimer]

I think that is what the OP is asking, probably could have been stated differently.

Something like...I think I have xyz relay failing, could the failure of xyz relay be why my glow plugs are not being energized when I try to start my New Holland 1725 tractor?