I think it would be the over heat cut out. If it was the pull in relay it wouldn't start. If it was the preheat relay I would think you would be hard to start. You can double check this by checking for voltage to the glow plugs.
If it is the overheat relay you run the risk of the pto not shutting off when the tractor overheats. So a higher risk of more damage caused by overheating.
Also this relay only comes into play during overheating so if you haven't overheated all would appear ok.
If it is the overheat relay you run the risk of the pto not shutting off when the tractor overheats. So a higher risk of more damage caused by overheating.
Also this relay only comes into play during overheating so if you haven't overheated all would appear ok.