Help needed as always

[vmen84 61]

First and foremost I hope everybody's been doing well been busy with class so I haven't been able to get on very much. As always I have a question so I think I may have figured out my problem every time I go to start the mower it won't turn over but when I put the battery charger on it on 10 Amps it starts right up after I put it away it won't start until the battery charger is back on it I think it's either the alternator or regulator but How would I find out? And How much does an alternator for a b 100 cost.

Thanks again for all the help

[953 nut 52,311]

With any electrical problem the first thing you need to do is thoroughly clean and tighten ALL electrical connections. Probably you have a corroded connection that is not allowing the battery to do the job and the added potential provided by the charger is helping overcome it.

[ClassicTractorProfessor 5,289]

[BOB ELLISON 2,976]

sounds to me like its a bad battery. I had one that did the same thing and it had a bad cell ,check the voltage then put battery charger on it

and let it set for a day, then check the voltage again if it has gone down by a half volt it more then likely is bad cell. And do what

953 nut said clean all connections first. Before I would start putting money in alternators or regulators I would  change the battery

it would only be about $30.00 or $35.00.

[vmen84 61]

the sad part is the battery is brand new 

Edited October 30, 2016 by vmen84

[BOB ELLISON 2,976]

1 hour ago, vmen84 said:

the sad part is the battery is brand new 

Does it click when you try to start ? Does the lights work ? It still could be a bad battery try what I said charge it and let it set . Check voltage before charge  and after it sets . A new battery should be about 12.5 volts after charge and never go below 12 volts after setting for 4 or 5 hours.

Also if you have a volt meter  connect it the battery and watch it as you crank see what voltage drops to. Could be a bad ground or wire going to starter.

Edited October 30, 2016 by BOB ELLISON

[daveoman1966 3,637]

A very common problem is that the RECTIFIER is not grounded due to corrosion between it and the mounting surface.  If it isn't properly and securely grounded, it will not feed charge to the battery.

Take it off of the tractor and thoroughly clean the corrosion from it as well as from the mating surface where it is bolted down.  Also clean up the male spade terminals on it  and the female spades on the end of wiring feeds. Battery terminal cleaner is available for this and works well.

[KC9KAS 4,741]

8 hours ago, daveoman1966 said:

A very common problem is that the RECTIFIER is not grounded due to corrosion between it and the mounting surface.  If it isn't properly and securely grounded, it will not feed charge to the battery.

Take it off of the tractor and thoroughly clean the corrosion from it as well as from the mating surface where it is bolted down.  Also clean up the male spade terminals on it  and the female spades on the end of wiring feeds. Battery terminal cleaner is available for this and works well.

I actually use a wire with 2 eyelets...one on the rectifier/regulator and the other to the negative side of the battery.

I eliminate that posible problem real quick!

[ohiofarmer 3,164]

8 hours ago, daveoman1966 said:

A very common problem is that the RECTIFIER is not grounded due to corrosion between it and the mounting surface.  If it isn't properly and securely grounded, it will not feed charge to the battery.

Take it off of the tractor and thoroughly clean the corrosion from it as well as from the mating surface where it is bolted down.  Also clean up the male spade terminals on it  and the female spades on the end of wiring feeds. Battery terminal cleaner is available for this and works well.

 Thank you for that. I have an engine that needs a coil, points,condenser, and switch to convert it from another type of electrical system. I will install all these before pulling the trigger to purchase a new  [stator/alternator]. You may have saved me some $$ right there!

[wallfish 16,058]

15 hours ago, vmen84 said:

I think it's either the alternator or regulator but How would I find out?

 

Disconnect the rectifier/regulator and use a multi-meter to test. Set it to AC and test the two leads coming from the running engine. Stator produces AC voltage around 30-35v AC or so. 

If AC voltage is there, reconnect the rectifier/regular back up and measure DC voltage at the single terminal which charges the battery. Should be around 14v DC.

No AC = Stator

No DC = Rectifier/regulator

Simplest to just start out testing the output DC by measuring at the battery. Around 12v without engine running, around 14v with engine running. The spike in voltage = the system is charging.

It's also possible to have a parasitic drain somewhere in the electrical system which is draining your battery while the tractor sits idle.

 

[vmen84 61]

So I checked the  battery voltage when it was not started and it was 12 when I started it it was five so assuming it's the battery I'm also going to switch the headlights out for LED ones if possible.

[lynnmor 6,873]

Should be about 14 volts running, low voltage is the charging system.  Charge the battery for ten hours and then take it to a parts place that tests for free, by now you may have ruined the battery by not keeping it fully charged.  But you do have a problem other than the battery.