Apparent dead short in wiring, kills tractor

[hophornbeam]

Hi folks,
I have a 2005 GT2554 that up until now has been a great tractor. This electrical issue blows the 25amp fuse in the fuse holder that is connected to a red wire and a red wire with white stripe wire the instant the key is turned on. I have gone through and disconnected most of the easy to access wiring connectors that have red wires connected to them to attempt to isolate the area that the short/problem may be in,( disconnect the connector, turn on the key and pop goes the fuse) I believe I have ruled out anything in the engine area. At first I suspected the key switch, but I am not so sure - I put a jumper across the red and red/white stripe at the key switch connector and the fuse blew as well. I am at a loss here. Short of removing the wiring harness to view every inch of it does, any one have any suggestions? I have just got it tore appart to get easy access to the back up safety interlock and the brake pedal interlock and I am running low on fuses!! Thanks in advance for any help!!

[OldMachinist]

Have you pulled the three wire connector off the regulator/rectifier on the engine. After that one start pulling the connectors off the dashboard stuff one at a time. Here are some wiring diagrams that should help.

[hophornbeam]

Thanks for the diagrams. They may provide some assistance. On my model there is a 5 wire connector pin that that leads in under the motor tin work. I suspect this connects to the ignition / magneto parts that are typically clustered under the flywheel. I have disconnected this connector and the fuse still blows. My ignition switch has a 7 wire connector. My system has 2 - 25amp and 1 - 5 amp flat type automotive fuses. It has been suggested that there is a solenoid in the carburator that could be suspect. The voltage regulator has been also suggested as a problem. I am not a highly experienced small engine guy, but I have had a few apart to make repairs. Is the voltage regulator located under the engine cowling?

[OldMachinist]

What engine does your machine have?

[rcbe]

It has been suggested that there is a solenoid in the carburator that could be suspect.

That is the carb afterfire solenoid - usually located on the side/underside of the carb body and will have one or two wires leading into it. Disconnect to isolate for testing for possible short in solenoid body.
Another thought - prob may be the ignition sw itself......

[savageactor7]

Traced a fuse blowing episode on our 2550 to the lights. Hope you can find your short quickly.

[hophornbeam]

OldMachinist, thanks. the engine is a Kohler Command 23, CH23S.

rcbe, I can hear the carb solenoid actuating and I did consider the switch as a problem.

savageactor7. I don't believe this is going to be an easy find.

I located and disconnected the 3 wire connector as suggested by OldMachinist. No fuse blew when it was disconnected, reconnected a couple of times and blew a fuse. So then I removed it, tested between the terminals a found a complete circuit between one of the outside terminals and the centre terminal. At that point figured it was shorted out. Reconnected it to the wires for curiosity and no fuses blew. Reinstalled the **** thing and have just finished cutting grass for an hour and a half. %$%$@%%@%@%$@%$@!!!!! I found no obvious frayed or worn wires.

[OldMachinist]

The three wire connector is on the regulator/rectifier. The 2 outer wires go to the stator windings(alternator) and the center terminal charges the battery. The wire on the center terminal is likely violet color and is connected somewhere into the 12+ side of the system. If the center terminal on the regulator showed shorted to one of the stator terminal the regulator is bad or going bad.

[hophornbeam]

OldMachinist, that is good information to know. I suspect your assessment is correct. I will have to get a regulator on order to have when the next round of issues start.

[hophornbeam]

An update for those that are interested.
I believe I found the cause of my short problems quite by chance as it turns out. The power wire leading to the head lights had rubbed on the sharp corner the muffler shielding steel. I had the hood up in a shady spot looking for the source of another vibration and noticed a very small arcing between the wire and the shielding.
While did I not realise this earlier you say?? Well the plastic crap head light bulb holders had broken allowing the bulbs to vibrate too much and they were burned out.
Thanks to those that offered opinions. I believe one did say to isolate the lighting system.