bad alternator?

[BenQ]

The connecter of the posts on your regulater should be marked with a letter (B,A F,G). What are they on yours?
Also how many wires are coming out of your alternator and regulater?
If we can find which wire exites the stator in the alternator you can put battery voltage to it with a jumper wire. If the alternator work with the jumper then it's OK and your problem is the regulater or the wiring.

 

[moojamboo]

in order to get to the regulator we have to remove the fuel tank. we ran an "N" circuit voltage test on the alternator per the repair manual:

• 
  connected the volt meter red lead to the N terminal on the alternator
  connected the volt meter black lead to the ground of the battery
  with the engin at 1500 RPMs the volt meter reading was 0.17

according to the repair manual this means we have a faulty alternator. can anyone confirm this?

if the tractor is jumpable is there anything bad with using the tractor by jumping it untill we are able to get a replacement alternator?

will the tractor stall in the woods? will we cause damage to the tractor by doing this?

Thanks for the input

 

[mitch becton]

moojambo if you would call dan smith 617-680-1557 he is boston ma. but he has covered the northeast for years he is alternator/starter rebuilder he can help you through this and also put you in touch with a builder closer to you than can solve your problem and i am firm beleiver if a starter or alternator or generator can be fixed or rebuilt it is very highly a better product than you can buy in todays market this is his cell number just let him i gave it you. one simple test to see if the alternator is working is to put in on test stand and hook up to the post on back of unit it should go to full field which means the charging will be wide open if it is working correctly on 6 volt system will probably go as high as 9 volt then you shut it down as not to do any damage to unit also on the 12 volt it will go as high as 15 to 16 volt also shut down this will help you rule out one or the other of alt to regulator

 

[mitch becton]

on further research see if this is what you have your ford tractor has a japanese built 3 cyl motor built by shibaura if this is correct your alternator is hitachi number lt135-27 if this is correct the plug in on the back of your alternator is shaped like a "T" the top spade is the "N" the up and down one is the field this is where the power would come from back to the first reply i did if you have away to spin alternator even on the tractor with the regulator disconnected hook volt meter to the "F" spade and make sure it has good ground at this point the alternator should go to full field and top out about 15 volts it is non regulated with regualtor not hooked up let us know how this works if regulator is problem again dan smith in boston can help you with this

 

[moojamboo]

So we got the alternator and regulator tested. the regulator needed replacing and the alternator had bearings and brushes replaced. hooked everything back up with a new battery.... get 12.6 Volts from the battery while tractor off. turn the tractor on to 1500RPMs and still only get 12.6Volts. any ideas where the problem might be? the manual says the only way to test the alternator is to have a load tester. is there another way to see if the alternator is putting out the right voltage?

 

[mitch becton]

did you try to check alternator with regulator disconnected it should take the volt meter well past 14.5 in just a few seconds as i stated before this is called full fielding which implies the voltage is non regulated and will actually go till it pops a diode in the rectifier now on another point i would say the 12.6 voltage is actual battery power only and a no charge from alternator you possibly have a bad rotor which is the first part of the alternator to create power it is not uncommon for them to quit working do you remember what the slip rings looked like when unit was apart this is where the brushes run in the alternator

 

[Soundguy]

i'd have that reg and alt tested again!

 

[moojamboo]

the alternator was just bench tested at a local place which rebuilds alternators as a business. while they were testing the alternator they replaced the brushes and the bearings. they said that the alternator bench tested good and they recommended we look at the regulator. the regulator they said was bad and they sold us a replacement regulator which is a non-mechanical regulator (electronic).

we ran the tractor with the regulator disconnected. the voltage never got above 12.67 volts. we checked the continuity of all circuits between the regulator and the alternator and the continuity of the regulator and seems that the resistance is low or none for all of these.

the local shop says that the alternator is good. they said they will make a visit to our house to look at the tractor for a fee including travel time. is there a way we can independently confirm the alternator is good prior to having them come to the house? This is our first time using this company and with all the other testing we have done we question if this company is trying to get more money out of us or if the really did test the alternator correctly. They are the only company around which does this work and they were recommended by a local repair shop.

 

[Soundguy]

can they not test the reg and the alt on their own bench?

if it tests good on their bench.. go home.. hook it up not using the wire harness.. hook it up with jumper wires point to point, with charge wire straight to battery.

test battery first. a bad cell will pull down 2v and work the p!ss out of the alt..

once hooked up straight.. run it and check volts. it SHOULD work that way if it works on their bench AND the bat is good, AND you have no dead shorts that glow red and smoke when running...

post back

 

[moojamboo]

how would you hook up the alternator without the wiring harness? we have an alternator which looks like this

(click for lager image)

which connectors do we hook up to battery positive? negative?