John Deere 318 voltage regulator

[Hjfowler]

Hello,

Yesterday my 318 wouldn't do anything when I turned the key. No dash light, no nothing. I went and bought a new ignition switch and it fixed the problem. Or so I thought. It will run, but then it will cut out and then flare back up right before it completely stalls as if the key was being turned off. Then if it doesn't flare back up and stalls completely, I have to turn the key to off, then on and it will start.

I got it back home and I noticed as I was pulling into the garage, the battery was bubbling slightly. Very little fluid was coming out, but obviously not normal. Could this be a bad voltage regulator causing these things?

 

[texasranger556]

Easy enough to check, should be close to 14 volts at high idle. Clean battery terminals while you're at it.

 

[Hjfowler]

How do I check that? With a multimeter? I know nothing about electronics.

 

[texasranger556]

Yep. Select DC mode and measure between the battery posts wile it's running. Red goes to +/positive.

 

[Hjfowler]

Ok. Could a bad regulator be causing all of these issues?

 

[texasranger556]

Based on your previous issues with the lights I'd say you might have a couple things going on. Cleaning connections and checking charge voltage would be a good start.

 

[Hjfowler]

lol yea. I don't think I reported back about the lights. The oil light and PTO light were switched. All is well. There really wasn't an issue

 

[Coyote machine]

Your battery should NOT bubble. Wear safety glasses when working around the battery, especially now. If the battery is being overcharged by a bad voltage regulator it could explode in your face.
Check voltage before starting the engine and then as it is running. Anything over 14.25-14.50 Volts is too high.
Do not smoke or have any source of ignition near a questionable battery.
Report back results, and be careful.

 

[Hjfowler]

My wires at the ignition switch are frayed. Could that causing the cutting out? I took a picture, but I'm not sure how to add it. And how do I remove the metal plug that's inside of the plastic plug to make a repair. Does that make sense? I don't know how else to describe it. There are two wires that go to a metal looking "spoon" that's inside of the plastic plug. The metal "spoon" is plugged onto the ignition switch.

 

[texasranger556]

The fact that you changed the ignition switch and it changed the behavior suggests you could have a loose connection in that area. If it's a standard 5 prong plug then you can replace it with something like this.

Amazon.com : Stens 43-223 Wiring Harness : Lawn Mower Deck Parts : Patio, Lawn & Garden

You'll need a crimper/stripper tool and butt terminals to install it. Disconnect the battery before you start and write down where each wire goes before cutting the old plug off.

This plug doesn't explain the bubbling battery, so like I said you may have a couple things wrong. Listen to Coyote's warning about battery acid vapor.

 

[Hjfowler]

The fact that you changed the ignition switch and it changed the behavior suggests you could have a loose connection in that area. If it's a standard 5 prong plug then you can replace it with something like this.

Amazon.com : Stens 43�-223 Wiring Harness : Lawn Mower Deck Parts : Patio, Lawn & Garden

You'll need a crimper/stripper tool and butt terminals to install it. Disconnect the battery before you start and write down where each wire goes before cutting the old plug off.

This plug doesn't explain the bubbling battery, so like I said you may have a couple things wrong. Listen to Coyote's warning about battery acid vapor.

Great, thanks. I'm getting a multimeter today. So test it before starting, then fire it up and test it at WOT? Or should it be at a different throttle range? I really don't want an explosive issue haha.

 

[texasranger556]

Yes, your battery voltage should be right at 12 volts with no load. When running at full throttle about 14. Search YouTube for checking a battery/charging system.

 

[Hjfowler]

Great, thank you!! I'll report back this evening.

 

[Hjfowler]

I think I figured out how to post the photo. I order the plug you suggested. I'll pick up the other necessary tools today.

 

[Coyote machine]

First thing you ought to do is put on safety goggles, or at least safety glasses and gloves and carefully remove the negative battery wire connection from the battery and put it aside. THEN, look at how the wires at your ignition switch are laid out. If they are frayed to the point that they can touch together bare wire to bare wire, you could use electrical tape to temporarily tape each frayed wire so it cannot contact any other wire or any metal on the mower.
With a VOM, ( Volt-Ohm-Meter), put the black lead on the negative post of the battery and the red on the positive post. Read Voltage present in the battery, without the engine running. Next, hook up the negative battery wire and start the mower. Now read the voltage. It should be at 13.5-14.5 Volts Maximum. If it reads any higher immediately shut off the mower and re-disconnect the ground wire, (neg) at the battery. At this point, IF the voltage is higher than what I wrote, you have a n overcharging problem, likely caused by a bad voltage regulator. The Voltage regulator is likely a separate box, about the size of a pack of cigarettes, that has wires going to/from the alternator. It could also be part of the alternator, as in a integrated Vreg, but less likely.
Report back the results of the tests I outlined above.
I also suggest keeping the mower outside, away from anything that could catch fire if the battery/ electrical system were to catch fire due to over-voltage being present at the battery. Though unlikely, it's not outside the realm of possibility.

 

[Hjfowler]

First thing you ought to do is put on safety goggles, or at least safety glasses and gloves and carefully remove the negative battery wire connection from the battery and put it aside. THEN, look at how the wires at your ignition switch are laid out. If they are frayed to the point that they can touch together bare wire to bare wire, you could use electrical tape to temporarily tape each frayed wire so it cannot contact any other wire or any metal on the mower.
With a VOM, ( Volt-Ohm-Meter), put the black lead on the negative post of the battery and the red on the positive post. Read Voltage present in the battery, without the engine running. Next, hook up the negative battery wire and start the mower. Now read the voltage. It should be at 13.5-14.5 Volts Maximum. If it reads any higher immediately shut off the mower and re-disconnect the ground wire, (neg) at the battery. At this point, IF the voltage is higher than what I wrote, you have a n overcharging problem, likely caused by a bad voltage regulator. The Voltage regulator is likely a separate box, about the size of a pack of cigarettes, that has wires going to/from the alternator. It could also be part of the alternator, as in a integrated Vreg, but less likely.
Report back the results of the tests I outlined above.
I also suggest keeping the mower outside, away from anything that could catch fire if the battery/ electrical system were to catch fire due to over-voltage being present at the battery. Though unlikely, it's not outside the realm of possibility.

Thank you for the great information. I'll be honest, I'm quite nervous about that situation since I'm not knowledgeable about electronics. I've ordered a voltage regulator, new plug for the ignition switch, and I'll be getting a new battery. I think I'll replace these parts since all are original and the plug is in bad shape and the battery likely is no good. I'll try running this process once everything is replaced.

 

[BrokeFarmerJohn]

If your doing any crimping of butt connectors, your gonna need a good crimping tool, I used Chanel locks, I have two sets and they work great. Channellock 99 Crimping Tool with Cutter - Crimpers - Amazon.com

For wire strippers, I find it's best that you get a pair with the strippers at the nose like these. Klein Tools Kurve Wire Stripper/Cutter-1155 - The Home Depot

I had a voltage issue on my Husqvarna with a B&S engine, it was the opposite, my battery was dying on me while it was running.

Another thing you will want to put in is a few inline fuses like this Amazon.com: Parts Express ATC/ATO Water-resistant Fuse Holder - 1 AWG: Automotive

That will protect your wires from over current and melting, would prob keep your battery from cooking also, my mower has two, one is inline from the voltage regulator to the battery.

If acid boiled over, you need to take the battery out and clean anywhere acid could go, acid is highly corrosive and if left alone could eat its way threw metal. I'm not sure of the best way to clean acid, I would thing a heavy Base type cleaner? To neutralize the acid? Idk

Be very careful with liquid acid, if it contacts your eyes or mouth your most likely headed to the ER, it has the potential to burn your skin as well, a non absorbent glove is suggested until the battery is free of exterior acid, a trip to advance to have the battery checked wouldn't be a bad idea also, if it has caps you may have to top off the acid. Good Luck and be careful.

Always remember to disconnect the power(battery) before wiring anything up.

 

[Coyote machine]

Thank you for the great information. I'll be honest, I'm quite nervous about that situation since I'm not knowledgeable about electronics. I've ordered a voltage regulator, new plug for the ignition switch, and I'll be getting a new battery. I think I'll replace these parts since all are original and the plug is in bad shape and the battery likely is no good. I'll try running this process once everything is replaced.

You're welcome.
I would go about it differently, BUT I completely understand your concerns.
So first disconnect the ground, (minus/negative) battery cable, usually black color sheathing. Set it aside.
Then positive cable, (red), without allowing the wrench to come in contact with any metal part of the mower.
Then replace your ignition switch, AFTER taking a few pics of what goes where, wires, etc. Draw yourself a diagram if necessary.
Replace the switch with the new one. Same procedure with the new voltage regulator, pics, then remove and replace.
Now install the new battery, after making sure there are no remaining frayed, broken, loose or otherwise not secure wires anywhere on the machine.
Recheck to make sure the neg and pos cables to the battery are in the right place.
You should be able to start it and verify the output voltage as detailed earlier.
Now, if it doesn't start, there can be other reasons, which get more complicated, so lets get this far before going deeper.
You should gather the year and exact model of the mower, the serial number and what EXACT engine it has in it. These items tell the tale of what parts may be needed to make it run/run properly. There are numerous issues with these mowers, especially if the engine was ever swapped out, if a different ignition switch was installed, etc. So get all the data you can so you can post it here if we determine further investigation is needed.
Take your time, check everything overe, and don't panic; it's not rocket science, yet!

 

[Hjfowler]

If your doing any crimping of butt connectors, your gonna need a good crimping tool, I used Chanel locks, I have two sets and they work great. Channellock 9�9 Crimping Tool with Cutter - Crimpers - Amazon.com

For wire strippers, I find it's best that you get a pair with the strippers at the nose like these. Klein Tools Kurve Wire Stripper/Cutter-11�55 - The Home Depot

I had a voltage issue on my Husqvarna with a B&S engine, it was the opposite, my battery was dying on me while it was running.

Another thing you will want to put in is a few inline fuses like this Amazon.com: Parts Express ATC/ATO Water-resistant Fuse Holder - 1� AWG: Automotive

That will protect your wires from over current and melting, would prob keep your battery from cooking also, my mower has two, one is inline from the voltage regulator to the battery.

If acid boiled over, you need to take the battery out and clean anywhere acid could go, acid is highly corrosive and if left alone could eat its way threw metal. I'm not sure of the best way to clean acid, I would thing a heavy Base type cleaner? To neutralize the acid? Idk

Be very careful with liquid acid, if it contacts your eyes or mouth your most likely headed to the ER, it has the potential to burn your skin as well, a non absorbent glove is suggested until the battery is free of exterior acid, a trip to advance to have the battery checked wouldn't be a bad idea also, if it has caps you may have to top off the acid. Good Luck and be careful.

Always remember to disconnect the power(battery) before wiring anything up.

Thank you! Great ideas.

 

[Hjfowler]

You're welcome.
I would go about it differently, BUT I completely understand your concerns.
So first disconnect the ground, (minus/negative) battery cable, usually black color sheathing. Set it aside.
Then positive cable, (red), without allowing the wrench to come in contact with any metal part of the mower.
Then replace your ignition switch, AFTER taking a few pics of what goes where, wires, etc. Draw yourself a diagram if necessary.
Replace the switch with the new one. Same procedure with the new voltage regulator, pics, then remove and replace.
Now install the new battery, after making sure there are no remaining frayed, broken, loose or otherwise not secure wires anywhere on the machine.
Recheck to make sure the neg and pos cables to the battery are in the right place.
You should be able to start it and verify the output voltage as detailed earlier.
Now, if it doesn't start, there can be other reasons, which get more complicated, so lets get this far before going deeper.
You should gather the year and exact model of the mower, the serial number and what EXACT engine it has in it. These items tell the tale of what parts may be needed to make it run/run properly. There are numerous issues with these mowers, especially if the engine was ever swapped out, if a different ignition switch was installed, etc. So get all the data you can so you can post it here if we determine further investigation is needed.
Take your time, check everything overe, and don't panic; it's not rocket science, yet!

Thank you for all the info today! I feel much better about this process. I'll report back.