B2400 starting problem finally solved

[newbury]

I was trying to respond to this thread but the forum puked and here
s parts of what I resurrected for a REALLY good fix

Frank, heres the bottom line..Power flows from your ignition switch through your PTO, neutral and clutch safety switches.
To the starter solenoid (black/white wire??) When all the switches and battery etc. are new there is very little resistance.
After you get some time and some age in these components resistance builds up and eventually will cause a voltage drop by the time it gets to the starter solenoid. This voltage drop will vary according to temperature, humidity and other factors.
That's why some times it'll work and other times it wont. The starter solenoid needs approx. 9 volts to fully engage. Anything less and it wont fully make contact to send power to run the starter motor. Yes it will click, but needs just a little more "oomph" to fully seat on the contacts and allow the starter motor portion to run. Now instead of replacing all the components in the system to reduce the voltage drop. What you need to do is install a starter relay. Most, if not all modern machines have this feature now because of this very problem. Some companies figured this out a bit sooner than others and came up with a pre-wired relay kit with instructions (John Deere and Scag I know for sure). Now some guys like to do things on there own and run down to NAPA and get a regular low voltage relay or a good old fashion starter solenoid, wire it up themselves and fix this problem, which works just fine. However the good old fashion starter solenoids still need close to 9 volts to engage and still causes some problems. The low voltage relay is the best way to go.. I think it will work with as low as 4 volts. In my experience the easiest way to go, is to install the JD kit part #
AM107421. It's, like I said, prewired and comes with instructions and it's around 15-20 bucks. Basically the way it works is... The red wire goes to the Battery terminal of the starter, the black wire goes to ground. You plug the black/white lead that would normally go to your starter to the male purple connector of the relay and the female connector purple lead to the starter. I have solved this "mysterious" problem many, many times on all brands and models of older machines with this kit. Everyone has given great suggestions for making sure your basic electrical system is sound and in proper working order. Most times when all else checks out and I have verified that voltage to the starter solenoid is a little low or questionable, installing this kit solves the problem at least 99% of the time. I'd be willing to bet it will work in your case as well. On rare occasions I have torn down the starter to find the contacts bad in the solenoid when this kit would not solve the problem. However for the price of the kit it's more than worth a shot in my opinion..................

tinab: Glad to help a neighbor (I live in Ballston Spa): Here is the wiring hook up for the low voltage relay (also in my 8/18/2010 posting in this thread) :

Re: B2400 starting problem finally solved

I have a printed copy of Kubmech's response to the starting problem. Per this response the low voltage starting relay is hooked up as follows:

Red wire goes to battery terminal of the starter.

Black wire goes to ground.

You plug the black/white lead that would normally go to your starter to the male purple connector of the relay and the female connector purple lead to the starter.

Hope this helps.

plus a link
pictures

 

[JWR]

Kubmech: I called up the local John Deere dealer, told him the part number, he had it in stock and I picked it up. I don't understand why Kubota doesn't offer a low voltage relay kit to fix this problem. I guess when the dealer replaced the ignition switch, it lowered the resistance so just enough current got to the solenoid to make it work. As the switch aged, the resistance increased causing enough of a voltage drop so the solenoid wouldn't engage. Thanks again for your help.

They do. Kubota dealer here calls it a "hard start kit."

Just See Post #84.

 

[JWR]

Eleven years after the first post in this thread and it is still helping people.

The JD relay kit fixed the starting problem on my B2400.

jb

And now 20 years after that first post it is still useful to many people. There is SOME confusion in this VERY long thread abut exactly what the fix is doing but the core of the solution is:

Install a relay triggered by the low current trigger signal from the start switch normally driving the solenoid. Have this newly added relay (which does not require a robust 12v to trigger it) put the full direct 12v from the battery on to the solenoid. That bypasses myriad voltage drops through safety interconnects, etc. and gets a full 12v direct from the battery to the solenoid. John Deere sells a kit for this purpose (links to that elsewhere in this long thread) and so does Kubota (in a copycat mode after Deere) and Kubota dealers here call that kit a "hard start kit."

 

[JWR]

Gator6x4, thanks for the input. Good info. Based on your diagram the relay is providing "more" current to the solenoid. That clearly indicates that (for whatever reason) the solenoid is not getting adequate current during starting at times. One would have to think it is marginal all the time and just "working most of the time" without the relay. Apparently any means of providing more current to the solenoid during initial start triggering works and from all the anecdotes from many people, works well. My remaining puzzle is why, then, does tapping on the starter also clear the problem for the moment? Maybe multiple issues or maybe that just moves the brushes or connections inside the starter a tiny bit allowing more current flow? Seems far fetched. I'm really wanting to discuss this with my Amish friends in the starter/generator/motor repair business. Good discussion !

My mistake: it is failure to get adequate VOLTAGE (not current) to trigger the solenoid.

 

[CalG]

My mistake: it is failure to get adequate VOLTAGE (not current) to trigger the solenoid.

Make no mistake/

If the Volts aren't getting where they need to be, there is a sever shortage of amps.

Volts have never done a lick of work over the entire history of electricity, It's AMPs that do the moving and shaking!

Whatt were electric eels called before electricity was discovered? ;-)

 

[JWR]

Make no mistake/

If the Volts aren't getting where they need to be, there is a sever shortage of amps.

Volts have never done a lick of work over the entire history of electricity, It's AMPs that do the moving and shaking!

Whatt were electric eels called before electricity was discovered? ;-)

Oh balderdash... not the case. The other name for voltage is "electromotive force." As an electrical engineer I will neither pull rank on you nor argue the semantics. Strictly the facts Ma'M as Dragnet used to say... I will state the facts once more:

In this specific circumstance:

• the VERY common problem on most brands of small tractors is that VOLTAGE DROPs occur sequentially across each of 6 or 8 or however many safety interlocks and/or poor connections there are between the battery and the starter solenoid.
• By the time the VOLTAGE gets to the solenoid it is slightly too low to trigger the solenoid.
• There is no such thing as a "shortage of amps." That is a badly misleading description. Current flow, measured in amps, simply will never occur until the EMF (voltage) gets high enough to cause adequate current to flow and operate the solenoid. The amount of voltage required is a design parameter for the solenoid.
• This reality is why a battery charger will usually overcome the voltage drops at places from the battery to the solenoid and thus facilitate starting for people with this problem -- nothing to do with the level of charge in the battery but rather because the charger is putting out typically 13.8V while the battery (in best charged form) is just 12v. The 13.8v is often enough to overcome the various voltage drops on down the line getting to the solenoid. The solenoid "needs" (is designed for) 12v without a lot of tolerance.
• The most common and effective solution (reported a dozen or so times with YEARS of success in this too-long 105 post thread) is a relay placed at the solenoid which is easily triggered by a lower voltage making it down the lossy path through all the safety interlocks and poor connections. These relays are designed to close & operate with around 7 or 8 volts rather than the full 12v. So this added relay kit secondary side applies the full battery voltage tapped from the adjacent heavy cable direct from the battery to the solenoid. That activates the solenoid which engages the starter and the engine then cranks. The extra relay kits are sold by Deere and by Kubota (and others.) Kubota calls them a "hard start kit."
• END of Story.
• Note: There us nothing that can be accurately described as a "sever shortage of amps." Unlike the chicken and egg which can be argued first versus second... Voltage is inherently first and Current is inherently second as a result of the voltage in the context of that solenoid.

 

[CalG]

Oh balderdash... not the case. The other name for voltage is "electromotive force." As an electrical engineer I will neither pull rank on you nor argue the semantics. Strictly the facts Ma'M as Dragnet used to say... I will state the facts once more:

In this specific circumstance:

• the VERY common problem on most brands of small tractors is that VOLTAGE DROPs occur sequentially across each of 6 or 8 or however many safety interlocks and/or poor connections there are between the battery and the starter solenoid.
• By the time the VOLTAGE gets to the solenoid it is slightly too low to trigger the solenoid.
• There is no such thing as a "shortage of amps." That is a badly misleading description. Current flow, measured in amps, simply will never occur until the EMF (voltage) gets high enough to cause adequate current to flow and operate the solenoid. The amount of voltage required is a design parameter for the solenoid.
• This reality is why a battery charger will usually overcome the voltage drops at places from the battery to the solenoid and thus facilitate starting for people with this problem -- nothing to do with the level of charge in the battery but rather because the charger is putting out typically 13.8V while the battery (in best charged form) is just 12v. The 13.8v is often enough to overcome the various voltage drops on down the line getting to the solenoid. The solenoid "needs" (is designed for) 12v without a lot of tolerance.
• The most common and effective solution (reported a dozen or so times with YEARS of success in this too-long 105 post thread) is a relay placed at the solenoid which is easily triggered by a lower voltage making it down the lossy path through all the safety interlocks and poor connections. These relays are designed to close & operate with around 7 or 8 volts rather than the full 12v. So this added relay kit secondary side applies the full battery voltage tapped from the adjacent heavy cable direct from the battery to the solenoid. That activates the solenoid which engages the starter and the engine then cranks. The extra relay kits are sold by Deere and by Kubota (and others.) Kubota calls them a "hard start kit."
• END of Story.
• Note: There us nothing that can be accurately described as a "sever shortage of amps." Unlike the chicken and egg which can be argued first versus second... Voltage is inherently first and Current is inherently second as a result of the voltage in the context of that solenoid.

You are so right! The volts do arrive first! And then those lazy assed volts just stand there with whips and loud voices to drive any available amps through any and all resistance.
But as for activating a solenoid,? Volts just stand with hands in pockets looking for amps to come around. Static electricity at it's finest! Think about it, Voltage can be measured across the finest wire , Where even micro amps will cause heat that burns the conductor asunder. HEAT is work! And volts don't do a lick of work...Not EVER!

I can get all the volts anyone could ever need by rubbing a rubber balloon over the old dry hair on my head. Thousand of 'em!

Amps on the other hand ... like hen's teeth to a man with nothing but a balloon for tools.

 

[JWR]

 

[Shropshire_Lad]

I have a printed copy of Kubmech's response to the starting problem. Per this response the low voltage starting relay is hooked up as follows:

Red wire goes to battery terminal of the starter.

Black wire goes to ground.

You plug the black/white lead that would normally go to your starter to the male purple connector of the relay and the female connector purple lead to the starter.

Hope this helps.

Sorry for the daft question...

I understand the purple connectors and black connector. Do I need to remove the exisiting red cable or just add the red from the solenoid to it?