[respondback]

Hello everyone.

I have a 20 year old Craftsman Lawn Tractor model 917.271142 with a Kohler 16.5hp engine.

It's been great, but yesterday after starting it, it ran for a few minutes and then shut down. I had a similar problem last year and it was a blown fuse, which after replacing it ran fine for almost a year.

I put in a new fuse and the same thing happened twice.

One other thing I noticed was that the tractor ammeter was reading higher than normal (the needle was almost all the way to the right - it's usually in the center).

After some browsing through the forum the likely culprit is pointing to a short somewhere. I did a cursory look of the wires, but I don't see any chafed wires, or wires rubbing.

I'm thinking of replacing the Solenoid and possibly the regulator/rectifier as the next steps.

Any other advice from the experts 😊 ?

Here's the wire schematic BTW:

 

[JP Savage]

Welcome to the forum.
Hope one of us can help.

First thought is to not throw parts at it. There is a shorting wire some where. Ammeter is telling you that.
Need to do more than a cursory look at the wires. Need to eye ball or feel with fingers along full length of each wire. And all around each side of the wire. Especially where they hide behind a metal bracket.
Pain in the butt I know, but is the best way to find it.

If ammeter is pegged to the right, you may be able to watch it as you move a wire. If it goes back to center, you may have a better idea which wire/wires are suspect.

Test probe with a 12V bulb in it may help also. If a wire is hot, and should not be, you are on the right track.

 

[PA318Guy]

Clean all cable and wire connections to include both ends of cables to the battery. Corrosion at connectors can increase resistance, in worst case you may have to even change out battery cables with new ones. But do all your connectors to get the best result.

 

[GardenTractorGuru]

Could be you fuel shut off solenoid could be drawing too much amperage like a broken wire inside or something. It would also explain it shutting off.

 

[respondback]

If ammeter is pegged to the right, you may be able to watch it as you move a wire. If it goes back to center, you may have a better idea which wire/wires are suspect.

Test probe with a 12V bulb in it may help also. If a wire is hot, and should not be, you are on the right track.

Thank you JP.

I should clarify that the ammeter was pegged to the right only while the tractor was running. I don't recall if it stayed pegged after I replaced the fuse and it wasn't running.

Also, can you please say more about the "Test probe with a 12V bulb" - I don't have one, but if I did how do I test the "hot" wires?

 

[respondback]

Could be you fuel shut off solenoid could be drawing too much amperage like a broken wire inside or something. It would also explain it shutting off.

I think it shut off when the fuse blew. I replaced the fuse and it started again then died in 2-3 minutes.

 

[JP Savage]

I think these are sold at all auto parts stores. Many hardware stores will carry them also.
Should be $20.00 or less. Shoot for one around $10.00
Needs to be a 12 volt test light not 110V.

Attach clip to ground (Negative)
Touch probe to positive. Bulb in handle will light.
Use needle end of probe to touch a wire that is suppose to be hot. Bulb will light.
Make contact with a wire that is hot, bulb will light. If not suppose to be hot, trace that wire to find where the short is.How to use testerlink to u tube

Hope some one will come along that can explain it better.

 

[Alien5044]

You can buy a cheap continuity tester at almost any hardware or auto supply store. It looks like an ice pick with a wire and alligator clip on it and a bulb in the handle.

Here is what I would try. Connect the tester's alligator clip to the positive battery terminal. Remove the start key and be sure all switches are turned off.
Then, I'd poke each terminal on the back of the ignition switch. I might be wrong, but with the tester connected to positive, the only one that should light up is the ground terminal.

At least you'd know what circuit to chase for chafed wires, or damaged parts that are grounding out and blowing the fuse.

If any others light the light, it would indicate a connection to ground...or a short.

Maybe other members can double check me on this.

 

[respondback]

View attachment 2510436

I think these are sold at all auto parts stores. Many hardware stores will carry them also.
Should be $20.00 or less. Shoot for one around $10.00
Needs to be a 12 volt test light not 110V.

Attach clip to ground (Negative)
Touch probe to positive. Bulb in handle will light.
Use needle end of probe to touch a wire that is suppose to be hot. Bulb will light.
Make contact with a wire that is hot, bulb will light. If not suppose to be hot, trace that wire to find where the short is.How to use testerlink to u tube

Hope some one will come along that can explain it better.

Thanks JP.
This maybe a stupid question, but how do I know which wires are supposed to be hot (besides the red wire that is)?

Also, wouldn’t you have penetrate the wire with that probe leaving a small hole?

 

[GardenTractorGuru]

Look through the wiring diagram and see what wires are connected to the battery.

Yes you might need a wire penetrater

 

[38racing]

don't really have any advice. I find that schematic interesting. I thought that maybe blown fuse was de-powering an antibackfire solenoid on your carb but I can't find it on the schematic. It shows the possibility of an optional inline fuel line shutoff. Bit different but again since it appears electrically controlled that could cause shutdown. What I've never seen before is the 2 yellow wire to the regulator that would test about 28v AC across each other seem to be able to connect to each other in operator presence relay #2 normal position (30 to 87a). I don't know what that's all about.

 

[respondback]

don't really have any advice. I find that schematic interesting. I thought that maybe blown fuse was de-powering an antibackfire solenoid on your carb but I can't find it on the schematic. It shows the possibility of an optional inline fuel line shutoff. Bit different but again since it appears electrically controlled that could cause shutdown. What I've never seen before is the 2 yellow wire to the regulator that would test about 28v AC across each other seem to be able to connect to each other in operator presence relay #2 normal position (30 to 87a). I don't know what that's all about.

There is no fuel shutoff.

 

[Alien5044]

If you connect the tester to the positive on the battery, then when you touch non grounded wire it will not light up.
The purpose of doing it this way is to find a wire that is grounded and might the circuit where your short is causing the fuse to blow.
In the switch diagram, the red arrow points to the only lug that should be grounded and light the positive connected test light.
Sort of like pulling on each door to see which one is unlocked.

You shouldn't have to penetrate the wire itself. On the back of the switch, see image below, are lugs where connectors are pushed onto the lugs. Just poke the tester at the base of the lug to see if any one of them lights other than the ground lug. Test your tester by being sure the ground lug lights it up. Most switches look similar to this one. Only one lug goes to ground, the rest are to other circuits such as lights, starter, or the PTO etc. With all things in "off" and the key removed, only the ground lug should light the positive connected tester. If one of the other lugs lights the light, then follow that circuit and its wires to see where it is grounded out.

 

[respondback]

If you connect the tester to the positive on the battery, then when you touch non grounded wire it will not light up.
The purpose of doing it this way is to find a wire that is grounded and might the circuit where your short is causing the fuse to blow.
In the switch diagram, the red arrow points to the only lug that should be grounded and light the positive connected test light.
Sort of like pulling on each door to see which one is unlocked.

You shouldn't have to penetrate the wire itself. On the back of the switch, see image below, are lugs where connectors are pushed onto the lugs. Just poke the tester at the base of the lug to see if any one of them lights other than the ground lug. Test your tester by being sure the ground lug lights it up. Most switches look similar to this one. Only one lug goes to ground, the rest are to other circuits such as lights, starter, or the PTO etc. With all things in "off" and the key removed, only the ground lug should light the positive connected tester. If one of the other lugs lights the light, then follow that circuit and its wires to see where it is grounded out.

Thank you - I ordered the tester from Amazon and it should arrive tomorrow.

Never done this before, so it'll be an adventure !

 

[respondback]

You can buy a cheap continuity tester at almost any hardware or auto supply store. It looks like an ice pick with a wire and alligator clip on it and a bulb in the handle.

Here is what I would try. Connect the tester's alligator clip to the positive battery terminal. Remove the start key and be sure all switches are turned off.
Then, I'd poke each terminal on the back of the ignition switch. I might be wrong, but with the tester connected to positive, the only one that should light up is the ground terminal.

At least you'd know what circuit to chase for chafed wires, or damaged parts that are grounding out and blowing the fuse.

If any others light the light, it would indicate a connection to ground...or a short.

Maybe other members can double check me on this.
View attachment 2510444

Can others confirm please that the "G" terminal should light up when testing and be the ONLY one that lights up and NOT the "B" (red wire)?

 

[JP Savage]

If you have the clip attached to the + (positive) on the battery, and touch the probe to the G terminal it should light up.
Wire from G terminal to the ground needs to be in place on the switch.

If you move the clip to the - (negative) on the battery and touch the B terminal on the switch, it should light up.

G is going to ground
B is from battery

 

[respondback]

If you have the clip attached to the + (positive) on the battery, and touch the probe to the G terminal it should light up.
Wire from G terminal to the ground needs to be in place on the switch.

If you move the clip to the - (negative) on the battery and touch the B terminal on the switch, it should light up.

G is going to ground
B is from battery

👍

 

[respondback]

So, all the wiring checked out - no bare wires, no rubbing, all connectors looked solid. Also did the test with the 12v test light and also no issues.

After reattaching the starter switch and the other connectors and the fuse, to my surprise the tractor started normally. Maybe some of the wires were loose, don't know, but I don't think this is an electrical issue.

I have now used it twice over 2 weeks for at least an hour each time with no issues.

Today when I went to start it, the engine would not turn over and after several tries, I could tell that the fuse blue again (the lights would not come on).

So I unplugged the starter switch, plugged it back in (not sure if that did anything), changed the fuse and to my surprise again the tractor started on the first try (but this time the engine turned over like it normally does) and again it ran for more than hour.

I did notice something strange (both today and last time) - there was an excess of fuel that was discharged from the carb in the front, so much so that there was a small puddle under the carb and it also left a spray on my shed floor.

What would cause it not to turn over - could it be the starter solenoid?
What caused excess fuel discharge from the carb?
How would I know if my carb is bad? I have never cleaned it in the 20 years that I owned it.

 

[JP Savage]

2 separate problems.
Better fix the fuel so is does not drip. Carb needs cleaning/rebuild. Dripping carb makes it easy to have a fire.

I would guess you still have a short somewhere. Or maybe neutral safety switch not making good connection when brake peddle is pushed in. Need to go back the the schematic and follow each circuit through to be sure each switch is doing what it should do.

Is there only one small wire on the starter solenoid? If so jump from positive on battery to the small connection on the solenoid and it should activate the switch inside. Click on and off as you touch the wire on and off. If it does, solenoid is good.

 

[respondback]

Thanks again JP. Replacing the carb is something I can do...eventually .

I've used the tractor and again it would not turn over at first, but this time no blown fuses. When turning the key to start it, all I heard is what sounded like 1 quick very, very brief turn of the engine and that's it. Your comment about the brake peddle not being pushed in intrigued me. So I modulated it a bit and the tractor started right up and run fine. So, what exactly would I need to do to determine if the issue is indeed with the brake peddle? Is it still wire related?

As far as the solenoid, do you think it's still worth pursing to see if it's bad? I mean if it's bad would it not work at all? Here's a picture BTW.