Try a "cold pull"
You may have a pinched wire, so try this before you get the engine warm.
Disconnect the battery POSITIVE, either via a switch or disconnecting the wire from the post so less chance of more damage, then get a test light, connect the positive lead to the positive post of the battery and the negitive lead to the fusible link at the starter end, the light should not light.
Test the setup by using a jumper wire to short the connection to ground, the light should light, once this is confirmed you are ready to go.
Now grap the wire and give it a tug, work your way up the wire all the way back to the other end, as you go twist and wigggle, when the place that is shorted is found the light will light up.
You may also need to press it against corners that is rubs, you get the idea, once you get the light to lite, then evaluate the wire tape it for now and continue until the whole thing is tested, now make a better repair to the wire and resolve the item that caused the damage.
Be very carefull, gentle pulling because you do not want the wire to move too much, you may fix it for a short period by moving the short away from its contact area.