D15 charging problem?
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Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=130187
Printed Date: 30 Sep 2025 at 9:48pm Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D15 charging problem?
Posted By: Tracy Martin TN
Subject: D15 charging problem?
Date Posted: 18 Oct 2016 at 7:49pm
I have a D15 series I that has stopped charging. I had genny checked and VR checked a year ago.Put a new VR on it, the mounting rubber has already failed. My starter generator altenator man has retired. What would cause it to not chage? I added a ground wire to battery ground and it didn't help. I notice discharge on meter when cranking, but no charge after it starts. What is best way to isolate my problem?Who has a good American made VR for it? I am not an electrical guru. Thanks Tracy
------------- No greater gift than healthy grandkids!
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Replies:
Posted By: cottonpatch
Date Posted: 18 Oct 2016 at 8:09pm
Napa sells Echlin VR. Solved my charging problem on series II 15. It was pricey at close to $80.
------------- '52 CA, '61 D10 II, ‘61 D15, '66 D15II, '63 D17D III, ‘69 170, '73 185 Crop Hustler, '79 185, '79 7000, '77 7040
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Posted By: Tracy Martin TN
Date Posted: 18 Oct 2016 at 8:25pm
cottonpatch wrote:
Napa sells Echlin VR. Solved my charging problem on series II 15. It was pricey at close to $80. | I will try them. Meantime I need help on diagnosing problem. Thanks Tracy
------------- No greater gift than healthy grandkids!
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Posted By: DiyDave
Date Posted: 18 Oct 2016 at 8:43pm
You might need to flash the fields, to polarize the genny. Search youtube, for a video of it. Also, pop the cover off the VR, and see if the tiny silver wire, inside has burned off because of a short, somewhere...
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Posted By: Brian Jasper co. Ia
Date Posted: 19 Oct 2016 at 12:15pm
Generators are easy to test Tracy. The first quick test I would do is run a jumper from the F terminal to ground and run the engine at half throttle and above. If it charges, investigate the F wire from the generator to the regulator. From there pull the belt off the generator and disconnect the wire on the F terminal at the generator. Using a heavy wire run from the battery negative if it's positive ground or battery positive for a negative ground system to the A terminal on the generator. A set of jumper cables works well for this. The generator should spin fast like a motor. While motoring, ground the F terminal. The generator should slow down, but continue to motor. If the generator passes these tests without excessive arcing at the brushes, it's good and your problem is elsewhere. Next step is test your wires. An ohm meter is not a good test method here because one tiny strand of wire will show very low resistance, however, that one strand of wire will not carry enough current to make the system work. My preferred test light is a headlight bulb. The bulb will pull about the same amperage as the field circuit does. Using a headlight bulb, make a simple circuit using each wire between the generator and regulator. Bright bulb = good wire. Do the same light test on the BATT terminal of the regulator. Bright bulb = good power supply to the regulator. The regulator needs a good ground through it's mounts. If you look closely you'll see on of the mounts has a wire connecting the body of the regulator to the mounting bolt. Buff off any rust under the mount making sure you have a good electrical path back to the battery ground. Still doesn't work? Replace the regulator. B&B Steve knows where the best quality regulators are available from. You can shine up the points inside the regulator and get it working again, but that is typically a short term repair.
------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford
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Posted By: Tracy Martin TN
Date Posted: 19 Oct 2016 at 9:49pm
Brian, I will try this. Thanks Tracy
------------- No greater gift than healthy grandkids!
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Posted By: TNBrett
Date Posted: 20 Oct 2016 at 4:50am
If you find you need a new rebuild shop, I've had great luck, and reasonable pricing from A&B starter & alternator. They're in Nashville
on Foster Ave.
Brett
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Posted By: Steve in NJ
Date Posted: 20 Oct 2016 at 8:46am
One of the most overlooked problems with a non charging Gennie is a poor ground or no ground. Always install a good ground off one of the feet of the VR to the engine block or chassis. If yer' lookin' for a rebuilder I can rebuild the unit for ya. Steve@B&B
------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife
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