Generator testing 6v positive earth.
 

Have a 6v positive earth generator and would like verification from the good people here if this is a test method to follow.

GENERATOR DOES NOT CHARGE:
Two brush Ford generators use the shunt type generator design. The field circuit has an internally grounded field. … unlike MoPar and GM which ground through the regulator. To test a Ford generator and/or regulator on the car, simply ground the field terminal at either the generator or regulator with the engine turning about 1000 rpm and watch the amp gauge (do not disconnect any wires) . Grounding the field removes all external regulation on the generator and it will go immediately to full charge mode. If the ammeter shows charge when you ground the field, the regulator is at fault. If the ammeter does not show charge, the generator is defective. Note the generator may have shorted out the regulator when it went bad.
Since the 6 volt regulators are still mechanical and can be set, it may be beneficial to know what is where inside them.

As another test method advises to remove the field wire from regulator terminal and move to armature terminal for test purposes and rum up to 2000 rpm and observe amps at amps meter.
Or are both ok?
Thanks,
Phil NZ

Re: Generator testing 6v positive earth.
 

If one end of the field is grounded like it is on a Ford 2 brush you need to feed current into the other end to make t work...not grounding that´s for GM generators...
Even if the generator is good you can get a no charge reading if the regullator is bad and the cutout in there is not closing.
Fast check is take fanbelt off apply power to field and arm on the generator it should then be turning like a motor...that will indicate if the generator is ok or not.

Re: Generator testing 6v positive earth.
 

Phil, the first part of your post is totally incorrect for a ford generator. Do not ground the field terminal at the regulator as it could cause damage to the regulator. The second part of your post is the correct method to test the ford system. REMOVE the field wire from its terminal on the voltage regulator and move it over to the armature terminal (NOT BATTERY TERMINAL) and place under the terminal screw. Start and rev the engine up to about 2000 Rpm which will allow the generator to charge flat out with a high ammeter charge showing if the generator is OK. What this does is bypass the voltage and current controls in the regulator but still has the cutout in the circuit. If the cutout is faulty then of course there will be no charge. The cutout can be temporally be bypassed by connecting the regulator battery wire over to the armature terminal an repeat the test whilst leaving the field wire still connected there also. If there is still no charge then the generator is faulty. Try that and report back your results. Regards, Kevin.

Re: Generator testing 6v positive earth.
 

Kevin
Thanks for the clarification on this. Will check it out as per the 2nd part of the post.
Phil NZ

Re: Generator testing 6v positive earth.
 

Kevin,
Its a 2 brush 6v generator positive ground. Just replaced armature and brushes.Was not showing any charging rate in normal set up. I had removed generator and regulator and took both th local Auto Electrical for checking. They checked and all ok?
Just now moved field wire over to armature terminal at regulator. Start up and rpm up around 2000. Shows high amps charging rate!! So generator is ok. Fault would be at voltage or current control on regulator?
How to determine which one it may be. Understand the regulator as fitted is a VW type regulator.
Thanks Phil NZ

Re: Generator testing 6v positive earth.
 

Phil, A VW type regulator is a two unit type and though it might work , it is not the correct type regulator to match your Ford two brush generator. See if you can find the correct 6 volt 3 unit regulator. The wartime ones as fitted to military fords were very good. I often see ford 6 volt regs on ebay. Be aware that some listed new ones which are made in China or India may not be good quality, its like a crap shoot with them. Also NOS or NORS regulators may not work straight out of the box and may require the contacts to be cleaned or polished because of some tarnish build up during long storage. Make sure what you buy is for the Ford system and not the field regulated to ground system as in many of the GM types. Regards, Kevin.

Re: Generator testing 6v positive earth.
 

Phil, make sure the regulator base is well grounded to the firewall of your car and maybe a ground wire from the base of the regulator back to the generator ground terminal or case. Regards, Kevin.

Re: Generator testing 6v positive earth.
 

The fitted regulator is a 3 unit type, was told it was VW but could be wrong.
Possibly just cut out to check, clean and adjust for correct operation.
Main thing is my generator is all good with a NOS armature ex ebay.
Hard to get the correct one to take the fan mounted pulley had to be 9.5" for armature length.
Phil NZ

Re: Generator testing 6v positive earth.
 

This generator does not have the ground terminal, relies on earthing through front mounting bracket to CI inlet manifold. Suppose extra earth could be a good extra.
Phil NZ

Re: Generator testing 6v positive earth.
 

Update,
today removed voltage regulator for a check. Cleaned up cut out contact, armature contact and field contact as well as all connections and mounts to firewall.
I set the gap for the armature and field contact at 25 thou. Not sure what these should be set to as the can be adjusted via side cover plate.
Fired it up and all is operating now as it should and verified by dash battery/amps gauge.
Is the 25 thou gap in the ball park?
Phil NZ

Re: Generator testing 6v positive earth.
 

Phil, you have not indicated the make and model of the regulator. Regs have all sorts of specs for contact gaps and armature air gaps. Did you measure the gaps before working on the regulator ? Check what voltage setting you have with some revs up. Should be around 7.2 to 7.5 volts at the armature terminal. Do you have some good close up pics of the regulator ? Regards, Kevin.

Re: Generator testing 6v positive earth.
 

Will get some details and a pic. Just contacted the local Auto Electrician who is familiar with the car, generator and regulator he confirmed 12 to 15 thou contacts gap. Will also check volts at armature terminal.
Appreciate your input and guidance Kevin.
Thanks Phil NZ

Re: Generator testing 6v positive earth.
 

Yes it would, connecting a wire from the case of the generator to the case of the regulator is a good idea.

Re: Generator testing 6v positive earth.
 

The 6v Voltage Regulator i am using is 6v Polamatic Blue Streak by Standard Motor Products. Not exactly sure of origin. Spent some time this afternoon checking and getting it as close to recommended 7.2 v at 1500 rpm.

RPM Armature battery.
700 5.0v 6.5v
1000 7.0v 6.4v
1500 7.4v 6.9v
2000 7.5v 7.0v


Attachment 407885

Attachment 407886

Initially was getting 9 to 10 v and took time to end up with above reading which i consider to be ok,
Phil NZ

Re: Generator testing 6v positive earth.
 

Phil, I am pretty sure your blue streak regulator is an after market unit and not supplied to any make of vehicle as original equipment. I think it was made in the USA. The voltage settings you have there are pretty good so leave it at that and see how it goes. Keep your eye on the battery acid level as a guide for any overcharging. Regards, Kevin.

Re: Generator testing 6v positive earth.
 

It was made in USA, found some info but not any clear instructions for this unit
The Standard Motor Products Inc who make the unit have been operating for 100 years. May try to contact them for some adjustment info.
Just to observe as you suggest for battery acid level.
Many thanks
Phil NZ