First, welcome to OCC.......
Next, the model of Tractor you have is a
1863.
The relay is part of the "safety features" to ensure the proper functioning of the Electric PTO with the operator's safety in mind. There are two other electrical switches that have an impact when this relay engages or not. Thus, just because the relay does not engage does NOT mean it is bad.
Lastly, we (OCC Forum) can/will NOT advise you to bypass a OEM Safety Feature.
Now if you want help figuring your problem out, please say so.