Need help to test charging system on Ford 3000

napo · Jan 3, 2009

Hello everybody and Happy new year 2009 !!!

My grand father has a ford 3000 since 1971 but this is now not working anymore... Problem is always the battery... i would like to change regulator but before I would like to test all the electrical circuit... Could someone help me or send me tuto explaining how to test it ?

Thank you in advance for him.

Robby

Belgium

dqdave1 · Jan 3, 2009

Hopefully you have a voltage tester. Check voltage of battery at battery terminals while engine is not running, key off. Should be 12 volts. Start tractor and while someone is starting tractor see what the voltage drop is while starting. After tractor is running, you should see an increase in voltage. Rev engine up and voltage should increase to 13 - 14 volts. If it does; regulator is working. If it does not , regulator is not working. If it is the original regulator, points may be stuck. You may want to just change it out. You may want to have battery tested also to rule out battery. Take it to auto store to have it tested. Clean all terminals well; including where ground wire connects to frame.

Soundguy · Jan 3, 2009

Your service manual should have a section on testing that OEM lucas generator and regulator..

In any case.. the advice to test bat votls before and after start are a good one.

Checking the battery with a specific gravity tester is a good idea too. a battery that, after being charged sets at less than 12.6v may be bad.. and if it's votls drop lower than about 9-10 when starting.. she's bad as well..

then you can full field the genny by jumping bat to field blade. ( arm and field blade are the only ones back there.. field is the small wire.

set throttle to mid idle.. jumping full field should make max charge.. so have meter ready on battery.. if no increase, then jump from arm to battery and full field.. this will rule out bad field circuit on the regulator and bad cutout.

if volts comes up on either test.. get a new reg.. I've seen them as low as 10$-20 on the net.. and for about 50$ at your local CNH dealer.

this is a B-circuit regulator.

soundguy

Thumper & Buttercup · Jan 3, 2009

Hey Napo,

Here is a web site with some photos that might help you out, it's on a car but the basics are the same, hope this helps.

Charging System Checks (Alternator Testing)

Soundguy · Jan 4, 2009

That might be great if he had an ALTERNATOR! Those fords came stock with GENNIES...

( even so.. if you know enough about electronics.. you can get some alternator regs to make gennies work.. B circuit gennies anyway... )

soundguy

Thumper & Buttercup · Jan 4, 2009

Hey Soundguy,

Maybe a Alt site but the basics are the same for checking out a Generator on a tractor. Just thought the pictures would help him.

Soundguy · Jan 5, 2009

The basics of an alt and generator are miles apart electrically.

Tell me how I would test the diode trio on a generator?

soundguy

Thumper & Buttercup · Jan 5, 2009

Hey Sound,

I would test the generator at idle, this is when the diode trio is putting out it's best, of course it adds to the voltage with increased rpm's. If there is a loss at idle then there is a problem.

Soundguy · Jan 5, 2009

News flash.. no diode trio in a generator... no rectifier's whatsoever...

good old dirty dc off the armature courtesy of fancy wiring and brushes..

That's my POINT!.. Sending someone to an alternator testing site doesn't send them down the correct road when they need to troubleshoot a DC generator. And as gens go.. that lucas job is a finicky one at that!

soundguy

Thumper & Buttercup · Jan 5, 2009

He sounded like he had never tested a system, the alt pictures would have helped the average guys some.

Maybe this will help, did a little digging but it answers the question better on the old generators.

Generators and Charging Systems

He gets a little technical for some but it better explains a diode trio better than I can.