Voltage regulator or loose wire hot, ground to frame, ignition switch etc. Have you checked for loose wiring, and all your ground connections? You may also want to check to see if there are any fuses in the charge wiring harness. I also need to ask if it drains while sitting, or just does not charge while running?

 

Welcome to the forum.

 

First off, Welcome. From your post, the first thing that comes to mind is a major current draw from the starter. Possible short or binding in the starter that sucks major current to overcome the binding.

Have any test equipment so you can measure voltage at various places in the circuit?

 

I had a similar problem - id charge the battery, run the tractor and it wouldnt start- turns out it was a bad diode from the stator charging wire - sucked the juice from the battery instead of charging it. New diodes can be bot for like $1 at radio shack - make sure its a 12volt type.

Id also check the starter like Mickey said- they can eventually draw a ton of amps when they start to wear out or get dirty -ive managed to 'restore' a couple of my briggs starters by pulling them apart,spraying the whole thing with carb cleaner, cleaning the armature with sandcloth and cleaning the contacts ( or you can replace them) - most briggs starters are easy to take apart n clean- IF they have an open end - ive used small L shaped pieces of wire to hold the contacts back while reassembling the starter - its worth a shot then paying $100 for a new starter.


A few of my tractors also tend to drain the battery while sitting , as wjjones mentioned - i simply unhook the battery when i park it.


Another thing to mention is what brand of battery are you using? A cheep low CCA battery or a high end high CCA battery? No matter what tractor you own, i always go with a good quality high CCA ( cold cranking amp) battery - low CCA batteries can be easily drained just starting them ( been that route- just wasting money)- high CCA batteries wont hurt the tractor, if you think it might- upgrade the battery cables to heavy duty type.

My one 90's craftsman GT5000 specifically states on the battery cable to use no less then a 600 CCA battery.

Another thing is when you buy the battery, insist on having them test it for voltage, sometimes theyll hand you a 3 year old brand new battery thats sat there in the shop all discharged before buying it - it probably wouldnt hurt to throw it on the charger either when getting it home for a bit to top it off.

Hope this helps you out.

 

Fixed it!

Thanks to every one who gave me advice and feedback. Based on input from several people I figured that to drain a battery down to zero would require a significant draw - so my gut said it's got to be the starter motor. Perhaps a short or something inside it. I bought a motor for about $50 and installed it. Zooom! It started right away with vigor. Should have followed my gut earlier...but that is ok...I spent so much time investigating and taking apart and inspecting that I am much more intimate with the engine. I found that behind one of the heat shields there was much debris that could have lead to an engine fire. Also found nuts and dried cat food stored in all the nooks and crannies. Obviously, some mouse has become quite familiar with the engine too. Not the first time. Usually, on the first start of the mowing season, dried cat food comes flying out of the engine as if I was spreading lawn fertilizer. Just hope I dont start growing cats instead of grass.

Thanks again,
bron

 

Glad you found the problem and get it fixed.

The second part of your post brings up an issue we all should pay attention to. grass and debris get past the intake screen and get lodged in the cooling fins and such. We all need to do ourselves a favor and at least once a yr pull the heat shields off and clean out the fins.

 

Hi, i have an MTD 760-770 model, my new battery also drains off while using the tractor, does it has an alternator to recharge while working on it? Or i should buy a charger?
Rgds.
Bill

 

Welcome,Bill007!
What engine is in it? Do you have the model/serial #'s. It would help.

 

Hi jhngardener367 thank you very much for your wellcome!
My tractor is a MTD and has a Briggs & Straton 500cc , Model # 13AN772S329 and Serial # 1E231B10034
Any help I'll appreciate a lot.
Rgds.
Bill

 

Bill, if you have a meter, check the voltage of the battery with the engine off. Next start the engine and put it at full throttle and check the voltage. If you don't have more voltage then the charging system needs attention. The info you gave is the MN of the tractor. You need to get the Model Type Code numbers off of the engine for further diagnosis.

 

I have a MTD # 14AR808K731 that drains batteries. I have replaced the battery. Please let me what to check.

 

Welcome o the forum!
That shows as a Huskee,from Tractor Supply,correct?
Has it got a Briggs engine ,or a Kohler engine ?
Either way, I'll need the engine #s ,to find out which type of charging system it has.