24 volt positive ground

frankieavalanche · Jun 25, 2018

I have a 750 case bulldozer loader . It is 24 volt positive ground. I am keeping it that way . I purchased new parts for the generator. (Bearings brushes&field coils). The field coils i took out have three wires, the new field coils only have 2 wires.I added a wire in between the two field coils.This is were the third wire was on the original field coils and wired them the same way but i still can not get the generator to work. I have polarized it every time i put it back on the machine. Any help would be appreciated.

Old Magnet · Jun 25, 2018

Is it a Type "A" (external ground with internal sourced field) or Type "B" (internal ground with external source field) unit? Makes a difference on how they are polarized. If not done properly you can "smoke" the regulator. Also make sure the regulator is meant to handle positive ground.

frankieavalanche · Jun 25, 2018

Thank you for your reply.I will take of the regulater tomorrow and check it.I purchased the machine 5 years ago.It was a basket case to say the least.But the engine ran good and was rebuilt.I did eveything else over and the charging system is my last hurdle.Also it was charging when i got it but the generater was in rough shape inside so i changed all the parts but can not seem to get it charging agian.I had the regulater off a few weeks ago .It was very clean inside all i did was clean the three sets of points.
What would i look for to see if it is Type A or Type B

Old Magnet · Jun 25, 2018

The difference is how it is wired as I described. If it is a Delco-Remy unit they are usually "Type A"
American Bosch are "Type B". They need to receive proper polarizing.

frankieavalanche · Jun 26, 2018

Hi Old Magnet
I posted pictures because i am not sure what i have.The field coils are the old ones.The new ones did not have the extra wire in the middle so i put one on.The. extra wire goes to the grounded brush terminal.If you need more pictures i can post more.Thank you for your help

Old Magnet · Jun 26, 2018

That is a correct match of generator and regulator. That is a "Type A" generator.
Field coils should be a Delco #1930237 and #1930236.
Do a motor test check on the generator:
There’s two parts to the Motor Test. First ground the FLD post to case/frame and apply voltage to the ARM post with case/frame grounded. If she spins good n smooth that says the Armature and Brushes and bearings are in decent shape. Then unground the FLD and she should speed up a bit, if so the Fields are likely okay, if not they may be bad (shorted or open) in which case she wont charge correct. If it passes BOTH tests, it usually will charge okay.

frankieavalanche · Jun 26, 2018

Yes its spins real good i have to hold it as it has a bit of torque.The first test i grounded the field post to the generater case.I then put positive 24 volts to the generater case and the negitive to the armature post.
The next test was ungrounding the field post and put negitive 24 volts to the field. Post and positive to the armature post and she spun a little faster

frankieavalanche · Jun 26, 2018

Well i put the generater and voltage back on the machine.I did test b with machine not running i removed the field wire from the voltage regulater. And momentarly touched to the battery terminal on the regulater.I then started the machine it is stll not charging .I checked with my volt meter.I have the same voltage running or not = 24.9 volts

Old Magnet · Jun 26, 2018

One more check:
Short field (briefly) to ground while running, should go to maximum charge. If it does than you need a regulator service (cleaning and adjustment) or possibly a new regulator.
If you need a new regulator, look into the electronic type replacement. The old mechanical ones are just about extinct.

frankieavalanche · Jun 26, 2018

I have some things i got to do .I will give it a try later.Just a thought, I purchased the fied coils on ebay .The only thing i thought abut was the series of the generater series 1105 so they fit but i wonder if it matters witch way field coils are wired. Could they be wired in reversed or does that matter

Old Magnet · Jun 26, 2018

Correct field coils should be selected to get the correct magnetic field. The generator doesn't care which way it rotates (brushes are normally mounted for one direction). Polarity is determined by the "polarizing process" before running the generator. In your case be sure to observe the "positive ground" polarity which is reverse of the more common negative ground systems.

frankieavalanche · Jun 26, 2018

I just tried shorting the field post while running.Not a spark.I am not getting anything from the generater.I used the volt meter on every configureration i could try i still got nothing

frankieavalanche · Jun 26, 2018

this is the field coil wiring i just copied from the old field coils. if the correct magnetic field is not right could this be the problem. I would think after a good bench test i would get something. I am going to try to polarizing it agian

frankieavalanche · Jun 26, 2018

I just polarized again armature post to regulator battery post. I am still not getting any reading from the generator with the wiring on or off. I know i am just missing something as the bench test showed it worked like
an electric motor so it should work like a generator

Old Magnet · Jun 26, 2018

Leave the field grounded and jump a wire across the voltage regulator Bat & Arm terminals. This by passes the cutout relay. If it still doesn't charge it's a bad battery, wiring problem or there's still a problem with the generator. Not having the right coils could affect the output capability but should still produce charging voltage.

frankieavalanche · Jun 27, 2018

I did the field grounded to the generater case jumped the battery wire on the relay to armature terminal still no go.I sent a picture of my new industrial batterys.I recharged them they were not down much they read 24.9volts.When i jump it on the regulater not running it is a very strong spark.When i jump it while running it is very weak. I would like to trouble shoot the generater by itself before i condem the voltage regulater.I can get a new regulater (
VOLTAGE REGULATOR 1969-71 FITS CATERPILLAR WHEEL LOADER 920 930 950 3304)
they sell them on ebay& Amazon. ca but its $132.00 .CAD plus shipping and hate to buy only to find out it is still the generater
Thank you for your time and patience i am not a quitter as long as you got ideas i will try them
Brian

frankieavalanche · Jun 27, 2018

I just finished diconnecting the. Ingnition wires from the generater and the field and armature wies from the regulater.I put two jumper wires to the generater to the regulaterAmatuer post to amarture terminal field post to field terminal. The contanuaty was good on the new jumper wires.I did the jumper wire on the field post to the generater housing.Then jumped the battery to amature agian running still no go.When i jump it not running it almost frys the wire.When running it is a small spark

Old Magnet · Jun 27, 2018

Zero output would indicate the polarity (north/south) magnetism is still not correct. What direction was the rotation when you did the motor test?

frankieavalanche · Jun 27, 2018

I just took the belts of and grouded the field put voltage to it it spins clockwise if you were standing in front of it

Old Magnet · Jun 27, 2018

Well for some reason my Delco-Remy Test Specifications skips the 1105228 model??? Must be a Case Specification. Clockwise rotation as viewed from the drive end is most likely correct. I'm out of suggestions, time to find a good generator/starter shop to test the generator and regulator.
Just for info unless you find new old stock regulator most are made in China and do not last.
Would appreciate knowing the outcome, good luck.
Here is the Electronic Regulator source I'm referring to:
http://cloversystems.com/products/other/dynamo-regulator/

24 volt positive ground

Active Member

Senior Member

Active Member

Senior Member

Attachments

Active Member

Attachments

Senior Member

Active Member

Active Member

Senior Member

Active Member

Senior Member

Active Member

Active Member

Attachments

Active Member

Senior Member

Active Member

Attachments

Active Member

Senior Member

Active Member

Senior Member