D15 no charge showing?
Printed From: Unofficial Allis
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=210740
Printed Date: 14 Apr 2026 at 12:30am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D15 no charge showing?
Posted By: Tracy Martin TN
Subject: D15 no charge showing?
Date Posted: 13 Apr 2026 at 3:17pm
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I know it has been asked a thousand times but....I charged my battery up. Cranked the tractor after a no start or try Saturday. It has generator and voltage regulator. Never had problem till now. Can i check the regulator while wired to tractor, can it be re polarized, which two post do you flash? How can I see if generator is working while still on tractor? Thanks, Tracy. ------------- No greater gift than healthy grandkids! |
Replies:
Posted By: DSeries4
Date Posted: 13 Apr 2026 at 4:04pm
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BAT and GEN to flash the generator. To check to see if the generator is working, check the voltage on the armature (A on the genny) and ground to the battery ground strap with a multi meter. Should be putting out over 12.5 volts. The generator might be due for a rebuild and good cleaning and a new voltage regulator as well. After decades of use, they do require maintenance every now and then. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Posted By: steve(ill)
Date Posted: 13 Apr 2026 at 4:37pm
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as Myron said, Ground the "F" terminal of the generator, then with tractor running, check voltage on the "A" terminal..... might show up on amp meter if the wire is good.. ------------- Like them all, but love the "B"s. |
Posted By: Leadoff
Date Posted: 13 Apr 2026 at 4:37pm
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Tracy Martin TN Consider cleaning the contacts/points on the Voltage Regulator - I have found that helps especially after winter idle period Good luck ------------- 1963 D17D Series III. 1965 D15 Series II. 1965 D17 Series IV. 1975 185. 1978 716H. 1979 716H. 1965 780 Harvester/1R&DC. 1957 Model 73 SC 4 Furrow Plow |
Posted By: DiyDave
Date Posted: 13 Apr 2026 at 6:42pm
Also, while you're in the regulator, as you open it up, see if anything that looks like solder drops out. There is a silver wire that can burn off, at about the speed of light, if someone "flashes" the wrong wires... ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: Tracy Martin TN
Date Posted: 13 Apr 2026 at 8:33pm
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Myron and Steve, is this correct, take one lead from multimeter and touch A on genny and other lead to battery ground? I got confused on the flashing and polerizing. Thanks, Tracy ------------- No greater gift than healthy grandkids! |
Posted By: steve(ill)
Date Posted: 13 Apr 2026 at 8:38pm
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YES... when you GROUND the "F" terminal, the generator goes to full output and your meter will measure between the "A" and battery ground ... you might need to take the "A" wire off the generator that goes to the regulator for the test... I dont think that will screw up the test, but possible if regulator is funky. ------------- Like them all, but love the "B"s. |
Posted By: Les Kerf
Date Posted: 13 Apr 2026 at 8:48pm
Just to clarify, this procedure is only for measuring the actual voltage, this does not polarize (flash) the generator. You do want the engine revved up a bit, even when working properly it won't charge much, if at all, when idling.
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Tracy Martin TN wrote:Posted By: TedN
Date Posted: 13 Apr 2026 at 9:47pm
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My grandad had a TD24 that would never hold polarity, it would be okay for a week and then quit charging. I eventually wired in a momentary switch to flash it. After that my grandad didn't need help when it didn't charge, he could just push the button. Not the correct fix, but it got the job done. Ted ------------- 190XTD seriesIII, 190XTD seriesI, maroon belly 7000, 7045, 190XTD series??? project(or maybe parts) |
Posted By: SteveM C/IL
Date Posted: 13 Apr 2026 at 9:57pm
| Plenty around here I can't seem to fix but I can make it work. |
Posted By: steve(ill)
Date Posted: 13 Apr 2026 at 10:04pm
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Tracy... just another comment... The Battery acts as a SINK or REGULATOR for the generator.. If the "A" terminal is connected to the battery, thru a amp meter or regulator, then you will read 14.6 volts when the engine is revved up... If you lift the "A" wire off , then the generator has no "sink" and it will go full output and might register 25v... Either way, the "F" has to be grounded....... as Les said, generators work by SPEED... more RPM means more VOLTS.. ------------- Like them all, but love the "B"s. |