This mower is about 7-8 years old ( est.). It is an RZ5424, ( 54" cut, 24HP Kohler engine ), model # 965881301. I bought it used, but it was in very good shape, and still is. But I had brought it out of it's winterization ( from my outbuilding ) this season, and have been through the following:

As I am getting everything ready to go, ( BTW, the battery was kept indoors all winter ), I had one battery terminal connected, and as I TOUCHED THE OTHER wire to it's terminal, ( for only a second or 2...NO LONGER ), smoke "boiled" out from underneath where the solenoid mounts, and some insulation melted off of a couple wires. I carefully inspected them, and wrapped them with electrical tape where needed. I have not attempted taking the entire wiring harness off as of yet. Right now, that's a little scary for me, but I will if necessary...VERY CAREFULLY, but I'll need to know where to begin, and a trace sequence to proceed. Does that make any sense? Hope so.

I bought and installed a new ignition switch (7-pole) and a new solenoid (2-pole w/ small yellow wire & spade clip in center) I double checked my black tape job...all OK. There are no headlights on the mower BTW.

I was told by a local mower mechanic that the 2 large red wires (from the starter and the battery) could be connected to either solenoid terminal...that either was OK. So, I had the large red starter wire to one solenoid terminal, the other from the battery to the other solenoid terminal, (here, I also have a small...perhaps 14 gauge red wire w/a connector, that comes out of the wiring harness, also connected on the battery side of the solenoid). Finally, one (approx. 14 gauge) black wire out of the harness, to ground...at least I assumed, and hoped, it was a ground wire. As I turned the key to start it up, (no smoke this time) a 20-amp fuse underneath the seat blew. I am pretty sure (90%) that this fuse is for the ignition switch. There is also a 7.5-amp there, which I believe is for the starter, ( not sure, though ). For the record, the blade engage, (I think it is also called the PTO, or safety switch), was pushed down, i.e., turned off.

I replaced the blown 20 amp fuse, tried to start it again. Once again, the 20-amp fuse blew. I know that I can go across the 2 solenoid terminals with a screwdriver and start it up, or at least turn the motor over. I had to do that the last couple of mowings last summer. I think that was necessary then, because the ignition switch had already gone bad.

i live in NC. All the trees are now blooming, and each day that passes, my lawn needs mowing more than the day before.

Can anyone give me any advice...perhaps a direction in which to proceed, to get my mower running again. I'm no expert, but have been told something along the lines of the voltage regulator and / or the alternator stator. I do not know where these are located, nor how to tell if either needs replaced. I am on a fixed income, and can't afford 50 or 60 bucks an hour for a mower mechanic. Any assistance would be very much appreciated. Thank you.

 

I think I would start with a thorough inspection of all wiring looking for perhaps a varmint attack? Could have chewed through some wires shorting them.....
I have found mice under the flywheel which is where your stator/alternator is.

 

Hi again BFHFixit,

Thanks for the reply, and the advice. I've broken this motor down to the point where I have the flywheel removed...no mice, LOL, nor any wire breaks that I can see. I haven't taken the starter off, but have felt most of the wiring under and around it, and feel nothing out of the ordinary, i.e., melted or touching wires. I have also carefully sanded the rust off both coils, plus a light sanding to the flywheel itself.

This motor is a model SV725S, in case that matters.. I have not yet cut away the zip ties to inspect THAT PORTION of the wiring within their black plastic sheaths. I also (again) have taken the solenoid loose, but left the wires connected. I think a priority (for me, personally) is to be CERTAIN I have it wired correctly.

I have one large red plus a small (approx. 14 gauge) red w/ a ring connector, from one side of the solenoid to the battery + side. The other large red from the starter to the - battery terminal. A 14 gauge black wire w/ ring connector grounded to the frame, underneath one of the solenoid mounting screws. I even scraped paint away from there before connecting that ground. I'm assuming THAT SMALL black is a ground, and not supposed to accompany the large red wire from the starter to the solenoid. Does a solenoid have polarity? I was told they do not. How can you tell if the voltage regulator is bad? Does the mower have to be assembled and in running condition first? Mine has three terminals, and all 3 wires are purple, if that means anything.

The stator is exposed, and even though I am doing this "on the fly", I see nothing wrong with it. All of the copper windings are shiny, and look good. I haven't removed it yet, and hoping I don't need to. The "connectors" along the wire paths all look OK when I unplug them, with no corrosion.

I'll reiterate I am no expert, but I wouldn't consider myself a "complete novice parts replacer" either. I have learned some things along the way with this "PUZZLE", which is exactly what it STILL is! As my rather large lawn keeps " laughing" at me, SO is my mower!! What in the world do I try next to solve this...WITHOUT a $50 an hour repairman? THAT'S WHY I began this "mega-dilemma" in the first place. Thanks so much for any knowledge you may be able pass along.

Tom

 

It is difficult to establish the sequence of your shorting problem to the switch replacement in the post. If the shorting has occurred since replacing the switch, you need to get a wiring diagram and verify switch terminations. If the shorting has occurred before replacing the switch, you need to get a wiring diagram and verify loads on the 20A fuse. At each load, remove all the wires on the 12 vdc terminal and verify there is not a short between this terminal and ground. Replace the load if there is a short.

 

To find a short, here is a quick easy way. Disconnect the negative cable from the battery, put a good fuse in, and connect a test light from the neg terminal to the negative cable. The test light will light up as long as there is a load. The light should not come on with the key switch turned off. If it does, begin unplugging different components until you find the plug that turns off the test light. If none do, you know it's shorted wiring and can track that down to a chewed/pinched/melted wire(s).

 

Cheese.
What is powering the test light if the switch is off?

 

Dear Forum Moderator cheese,

Very sorry, but I had my last post 99% finished, and it just disappeared. It's this sorry-a** Dell that I wish I had NEVER bought! Did you happen to see my post somehow? Because you are simply elaborating on a question where that had been the "meat"of my post. This just seemed truly coincidental.

I am now going to try the test light method. I will let you know later this evening the results.

 

A short on a power source to ground before the key switch. DC voltage flows from negative to positive. A test light can act as a resistor/load and keep from blowing the fuse.

 

Correct, the same thing that powers the light is what is causing smoke and blowing fuses... current. As long as there is a short, the light will burn this way.

Kleinscmidt, no, I didn't see any other post from you besides what is currently here.

 

Page 49 of this Manual has schematic for your mower as well as key positions.

 

Poster says fuse blows after closing switch, therefore the short is downstream of the switch and fuse. In Cheese’s scenario the switch is open. So I repeat my question. How is the lamp being powered? His scenario will only find a short in the positive wire (before the switch or fuse, whichever is first) to a negative (not ground) wire. The loads are not being powered.

 

BTW the 20amp fuse is the main battery voltage from the battery to the key switch. The 7.5amp is for the clutch.

Unfortunately where you observed this may not be the only place the same thing happened.

My next question it can you turn the key to "On" not start and the fuse still blow? Or only when you turn to "Start"?

You also have two positions for "Run" One position will run the lights the other will not.

On the red/black wire going to the switch, unplug the switch and measure voltage on the B terminal to ground.

That would be my first move then depending on the findings where to check next.

cheese may have some other ideas as well.

 

Your engine SV725 Courage should have a -**** after it on the label. I would need that to get the exact electrical of the engine, but there really isn't any thing there I am aware of going out or bad that would cause this. The engine does not use electricity it only makes it so.

 

Quote from the original post:

"As I am getting everything ready to go, ( BTW, the battery was kept indoors all winter ), I had one battery terminal connected, and as I TOUCHED THE OTHER wire to it's terminal, ( for only a second or 2...NO LONGER ), smoke "boiled" out from underneath where the solenoid mounts, and some insulation melted off of a couple wires."

This means there is or was a dead short that needs to be found. If it doesn't show up anymore, then you turn the key and disconnect the carburetor fuel shutoff solenoid and trigger wire for the solenoid and continue to check just as I described. The short will light the test light. Since we haven't gotten that far yet, I repeat the original advice to check first with the key off. You can't just start the diagnostic process in the middle. Well, I guess you can if that's how you want to do it but I'm not giving half cocked advice.

In any case, something shorted the moment the battery was connected and that needs to be found. It may have burned the wire up in the process and once that burned connection is found and repaired, the short will very possibly, even likely be right back.

 

Eureka! Found it. Began yesterday again tracing wires, looking / feeling for burnt or melted insulation(s). As it turns out, the initial touching of the negative wire to negative side of the battery actually WAS too brief to matter, it would seem.

i located the cause when tracing along the harness path toward the right side steering handle switch. A couple of zip ties had broken off, allowing that length of the harness to drop down low enough, so that the friction from one of the belt pulleys had burned AND melted four wires together.

A few simple snips, butt splices, and new "rubber tape reinforced" zip ties later, I was busy mowing the lawn! I don't know HOW or WHY I can now chuckle about it...I sure as hell wouldn't be IF I'd had to pay this bill to a mower repairman...because that "simple" fix likely would have ended up costing me a couple hundred bucks!!

A sincere thank you to ALL here, who have aided me in one way or another to my very relieved ending of the "nightmare" that is now behind me, literally, i.e., freshly cut grass! Again, I want to express my gratitude. Until next time, happy mowing!