Hey Tim, pull all the leads off the plugs and start one by one hooking them back up, should find the bad one. Probably best to replace all of them, hard telling how long they been in there. If a tip breaks off they can really mess things up. Torque for those is 120 +- 24 inch lbs. never seize them when installing.
What he said. Take them all off and tape each one up or make sure they are not touching anything. Then try it without them hooked to eliminate a short in the wire. Then one by one. Also it might just be the relay weak.
Where the wire in the conduit runs behind the Turbo could be the problem if the heat from the Turbo has cooked/burnt the insulation off the wire, I had to cut the conduit once and remove that section behind the Turbo, thereafter just had to make sure the bare wire did not come into contact with anything, on occasions put a bit of rag there as insulation to start the tractor, then removed the rag straight away before things got hot. If the conduit looks very burnt from heat would be a possibility.
Wombat