Fix for my G1800 with intermittent starter click but wont crank issue, probably applies to G1900 G2000 and others

Figgsit

New member

Equipment
G1800 B7510
Jun 16, 2025
2
0
1
Florida
I have seen people asking about this sometimes will crank and sometimes it wont but never a fix posted, that I saw. Mine would always crank with a jump or after a battery charge and would run and operate normally once started. Turns the connectors out of the alternator had developed resistance which dropped the charging voltage . It was still charging but it left the battery volts lower than should be. When trying to crank the starter solenoid couldn't pull the plunger fully to engage the internal starter switch. If you have this issue a quick check is the clear rubber connector covers had very dark brown spots from overheating. Clean connectors up, crimp them down a bit and put some ox-guard on them. Thinking back this issue started after I had a battery fail, jumped started and mowed. I guess the extra load on the alternator cooked the connectors and caused this issue. Happy mowin'
 

Spam Bot

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Windows Computer
Aug 3, 2024
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Austin, Minnesota
If your tractor is a diesel, then it doesn't require electrical current to keep it running after it is started. If it is a gasoline engine, then the ignition system requires current to keep the engine running. If the electric current weren't sufficient, the engine would have stopped running. In conclusion, I believe that poor connections are/were the cause of the issue, and nothing more. Electrical connections deteriorate when they are not tight, and when moisture gets into them. An inexpensive way to keep electrical connections clean and moisture-free is to use a slight smear of Vaseline on them.
 
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Henro

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B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
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If your tractor is a diesel, then it doesn't require electrical current to keep it running after it is started...
Granted this is true. BUT the OP stated, if he jumped the tractor or charged the battery it would start and continue to run normally, so gas or diesel is not relevant. The battery voltage was too low to pull the starter in fully apparently.

So it is likely the cure for the issue the OP was commenting on was indeed the corrosion at the alternator output terminals.

Dielectric grease is a great idea, and not expensive. BUT everyone has Vaseline in the house it seems. My choice would be to purchase a small quantity of dielectric grease...

Edit: I suppose it is possible his battery is approaching the end of its service life, and maybe self discharging on its own between starts...time will tell as continues to use the tractor.
 

Spam Bot

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Dielectric grease should not be used on metal electrical contact surfaces where electrical conductivity is crucial, as it is an insulator and can impede current flow. Specifically, avoid using it on the contact points of wires, connectors, or any components that need a solid electrical connection. It is also generally not recommended for large cable connections or where arcing is likely to occur.
 

lmichael

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Equipment
Kubota G2160
Apr 23, 2021
715
341
63
Rockford IL area
Short of a bad battery, bad ground somewhere, bad safety switch, or bad ign switch you will want to add in a helper relay in the starter circuit. I chased my tail all over my G2160 and finally had enough. Installed a helper relay over 3 years ago and hasn't skipped a beat
 
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Spam Bot

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Windows Computer
Aug 3, 2024
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Austin, Minnesota
Short of a bad battery, bad ground somewhere, bad safety switch, or bad ign switch you will want to add in a helper relay in the starter circuit. I chased my tail all over my G2160 and finally had enough. Installed a helper relay over 3 years ago and hasn't skipped a beat
I have never heard of a "helper relay". What is it, and how does it work? Do you have a manufacturer's part number that I could look up to see the specifications? thanks
 

lugbolt

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Equipment
ZG127S-54
Oct 15, 2015
5,430
2,126
113
Mid, South, USA
those old G series mowers were notorious for electrical problems. Maybe not so well publicized but the rest of the tractor is great, it's almost always electrical stuff that goes south on them

these require 12v to run (electric lift pump). They'll theoretically run without it but you'd have to feed the injection pump somehow..

starter "helper" relays are a godsend. Basically it's a 30a #87 relay installed in the starter solenoid circuit. Unplug the solenoid trigger wire (white?), and use that to trigger the relay on pin 86. Pin 87 goes to the starter. Pin 30 to the battery (or better/easier, on the starter's big wire that comes from the battery), and pin 85 goes to a good chassis ground. John Deere used to sell a kit specifically for mowers that had similar issues, part # was AM107421 but probably a new number now. It has the terminals already installed so all you do it plug it in and put the terminals where they belong. Super easy. BTW it only works with the "small" starters, some of the earlier G series used the "big" starter. The big starter had an external solenoid and had one large wire on the starter where the late starters were a gear reduction style starter with two wires (one large one small). If you have to replace a starter use the later one and wire it accordingly. That starter uses a lot less power to crank the engine and lasts nearly forever. Mine is still original-from 1994 IIRC.

run through the harness connectors and do a voltage drop test across all of them. Fix the bad ones. There is one below the steering wheel, underneath the tractor, that is almost always in bad shape. Hard to get at too but once you have the harness retention tab bent out of the way, you can get better access. The pins are often corroded. Similar for the voltage regulator connector under the steering wheel, behind the radiator. Almost always corroded if original. I've had to replace a bunch of those. On mine it was so bad that the wires were burnt, so I just removed the dynamo and put a regular 40A alternator on it that came off of a core BX24 engine from work (I worked at a dealer at the time). Not terribly hard to wire that in, and it bolts on-but you need to make sure to get the spacer (if you have seen a BX24 alternator setup, you know). There is a spacer on the pivot bolt and it is required. That or a stack of washers, it aligns the belt properly. It charges a little better at low speed (near idle) but it also needs a few wiring changes to be made at the reguator/rectifier in order to be done properly, and to run a good 10ga wire from the lug on the alterator to the starter, with a 50A slow-blow fuse inline. The only advantage is that it will charge a little better at lower engine speeds. The factory installed dynamo is plenty of charging power for the application though, and simpler. Not much goes wrong with them, maybe a bearing once in a while and they are simple to rebuild.
 
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Figgsit

New member

Equipment
G1800 B7510
Jun 16, 2025
2
0
1
Florida
Short of a bad battery, bad ground somewhere, bad safety switch, or bad ign switch you will want to add in a helper relay in the starter circuit. I chased my tail all over my G2160 and finally had enough. Installed a helper relay over 3 years ago and hasn't skipped a beat
No need for anything additional. Repairing the alternator connectors so the battery could charge fully fixed the issue
 

Old Machinist

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Equipment
Kubota LX3310 cab, JD 4310, NH 575E cab backhoe, JD F725, Swisher 60", etc.
May 27, 2024
330
337
63
NE FL
I have never heard of a "helper relay". What is it, and how does it work? Do you have a manufacturer's part number that I could look up to see the specifications? thanks
My Searay I/O powered boat has an external starter solenoid mounted on the engine in addition to the solenoid on the starter. They do that to get by with lighter contacts and wiring from the switch. Caught me off-guard a while back when one of the connections corroded on it.

My John Deere tractor has an intermittent no start that will kick in on subsequent tries like the solenoid is failing or the armature has a bad spot. I've noticed when I have it on the solar maintainer that keeps the battery at full charge it doesn't happen. It mostly happens when it's been sitting and not on the maintainer. Sometimes even after it's been running a while. It never fails to start but on occasion I have to turn the switch to the start position a couple of times before it does.
 
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lmichael

Well-known member

Equipment
Kubota G2160
Apr 23, 2021
715
341
63
Rockford IL area
Alternator was and is still charging perfectly. Other than I installed an Interstate battery from Costco (trust me they're junk but easy to get and cheap). First one I bought lasted not quite 3 years. They don't work well in cars either.
But thing is I can buy one at Costco for $80 or buy one at say Farm & Fleet (arguably a better battery) but over $200
My issues were all the support circuitry for safety switches not allowing enough currently to fully activate the starter solenoid
 

arml

Active member

Equipment
B5100e BX2200 JD455AWS G1800
Jan 27, 2022
221
235
43
Pennsylvania
those old G series mowers were notorious for electrical problems. Maybe not so well publicized but the rest of the tractor is great, it's almost always electrical stuff that goes south on them

these require 12v to run (electric lift pump). They'll theoretically run without it but you'd have to feed the injection pump somehow..

starter "helper" relays are a godsend. Basically it's a 30a #87 relay installed in the starter solenoid circuit. Unplug the solenoid trigger wire (white?), and use that to trigger the relay on pin 86. Pin 87 goes to the starter. Pin 30 to the battery (or better/easier, on the starter's big wire that comes from the battery), and pin 85 goes to a good chassis ground. John Deere used to sell a kit specifically for mowers that had similar issues, part # was AM107421 but probably a new number now. It has the terminals already installed so all you do it plug it in and put the terminals where they belong. Super easy. BTW it only works with the "small" starters, some of the earlier G series used the "big" starter. The big starter had an external solenoid and had one large wire on the starter where the late starters were a gear reduction style starter with two wires (one large one small). If you have to replace a starter use the later one and wire it accordingly. That starter uses a lot less power to crank the engine and lasts nearly forever. Mine is still original-from 1994 IIRC.

run through the harness connectors and do a voltage drop test across all of them. Fix the bad ones. There is one below the steering wheel, underneath the tractor, that is almost always in bad shape. Hard to get at too but once you have the harness retention tab bent out of the way, you can get better access. The pins are often corroded. Similar for the voltage regulator connector under the steering wheel, behind the radiator. Almost always corroded if original. I've had to replace a bunch of those. On mine it was so bad that the wires were burnt, so I just removed the dynamo and put a regular 40A alternator on it that came off of a core BX24 engine from work (I worked at a dealer at the time). Not terribly hard to wire that in, and it bolts on-but you need to make sure to get the spacer (if you have seen a BX24 alternator setup, you know). There is a spacer on the pivot bolt and it is required. That or a stack of washers, it aligns the belt properly. It charges a little better at low speed (near idle) but it also needs a few wiring changes to be made at the reguator/rectifier in order to be done properly, and to run a good 10ga wire from the lug on the alterator to the starter, with a 50A slow-blow fuse inline. The only advantage is that it will charge a little better at lower engine speeds. The factory installed dynamo is plenty of charging power for the application though, and simpler. Not much goes wrong with them, maybe a bearing once in a while and they are simple to rebuild.
Picture of relay on my G1800
relay.jpg
 
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