CK20 Wiring problem

[ruthere]

I would appreciate any help with a wiring problem with my CK20. Here is the story so far:
After being out in heavy rain I noticed the ignition switch was problematic but I could get it to function if I fiddled with it.
After a week or so of this I went to start it and burning smell form under hte hood. The wiring loom including the small earth wire from the battery to alternator and starter was completely fried.
I ordered new ignition switch, new loom and new timer relay.
Received new parts but they sent the wrong relay. Installed new loom and switch with old timer relay. It runs but will not stop presumably because the timer relay is dead. Managed about 3 hours of mowing in this state without problem.
New timer relay arrives and is installed. Engine turns over very slowly as though battery is low. Does not start then the familiar smell of burning..........
the small gauge earth wire has fried again. I caught it earlier this time and it doesnt appear to have taken the whole loom with it.
Conclusion - installing new timer relay has opened the bad circuit I had originally.
Replace old timer relay. Engine now turns over fast ( even faster than normal?) but will not start.
Seems like I have a short somewhere. How can I locate it ?
And why did the fuse not blow ??
Thanks for any suggestions. The grass is long after our wet winter and needs mowing!

 

[ritcheyvs]

It's hard to understand how the timer relay could do this because both of the 12v feeds to this relay have fuses. Something is wrong, obviously, but I can't help much without being able to look at the tractor. I don't know what you mean by "small earth wire." The fact you have the timer relay implies you have the older version with the stop solenoid mounted externally (on the right side of the engine) which operates via the manual mechanical stop linkages. If so, and assuming you can read a schematic, this schematic may help.

As a troubleshooting aid for starting, check if the glow plugs are getting power during the glow cycle and check that the stop solenoid is not being held in the stop/off position.

 

[hillwood]

Check the main ground wire from the battery to the engine block for good clean tight connection. The starter might not be getting a good path though the battery wire and it is trying to go through the other wires when you are cranking the engine.