CA 12 v conversion woes
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=192908
Printed Date: 20 Sep 2025 at 8:12pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: CA 12 v conversion woes
Posted By: captaindana
Subject: CA 12 v conversion woes
Date Posted: 13 Jan 2023 at 7:38pm
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Hey guys I put a new Denso one wire alternator new 12v battery new wiring new voltmeter new internal resistor coil tractor runs perfect does not show a charge I unhooked the wire coming out of the alternator and just ran motor wide-open and tested the alternator and nothings coming out is that normal with nothing hooked to it? Steve please I need a simple diagram. I have push/pull sw, volt meter, and pull rod to starter. Help please😂🤔. Thanks! ------------- Blue Skies and Tail Winds Dana |
Replies:
Posted By: steve(ill)
Date Posted: 13 Jan 2023 at 8:53pm
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one wire alternator should have one BIG wire ( maybe 8- 10 gauge) running from the BIG terminal to the Battery + terminal, or the other end of the + terminal at your starter lug..... Should be HOT all the time.. You need POWER to the alternator, and adequate RPM to get the alternator to Charge... If you have a volt meter, see that you have 12v at the alternator... you have a VOLT METER, so it goes in parallel with the alternator, not in series.. will get a simple picture. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 13 Jan 2023 at 9:07pm
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...here is a basic drawing.. --BIG wire from the alternator straight to the battery + or starter + cable --you have some type of ON- OFF switch to put power to the coil --the voltmeter gets it power from the OUTPUT of the switch --the other side of the volt meter is grounded or goes to the - battery post --the ON-OFF switch has one HOT wire input that comes from the + bat or + starter cable --you should read 12 volts at the starter lug and the alternator lug all the time, engine off  ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 13 Jan 2023 at 9:10pm
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If you have a MAG then your "OFF" switch will ground the mag... You still need an ON or POWER switch that puts power to the volt meter .... ?? right ? ------------- Like them all, but love the "B"s. |
Posted By: DaveKamp
Date Posted: 13 Jan 2023 at 9:27pm
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Dana- make absolutely POSITIVELY... that there's a good return (ground) path from the case of the alterator, to the battery's ground... It would be a good idea to take a jumper cable from that case, back to the grounded battery post... at least, for a test. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: Dakota Dave
Date Posted: 13 Jan 2023 at 11:30pm
| you said you ran it with the wire disconnected. It won’t produce any voltage with the wire unhooked it needs a battery hooked for it to energize. The one I had also would not energies at idle. I needed a 1000 Rpm for it to start charging. Once energized it charged fine at idle. |
Posted By: captaindana
Date Posted: 14 Jan 2023 at 4:35am
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Thanks to all whom replied…after another cup of coffee I’ll get on this! I’m shocked the ammeter and voltmeter are hooked differently! ------------- Blue Skies and Tail Winds Dana |
Posted By: AaronSEIA
Date Posted: 14 Jan 2023 at 5:52am
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From what I understand, an ammeter simply is a "pass through" gauge showing the amp load pulled where a volt meter is measuring battery/charging volts. Two different gauges with two different purposes. AaronSEIA
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Posted By: WF owner
Date Posted: 14 Jan 2023 at 6:34am
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Think of water. An ammeter is like a water meter that measures how much water is flowing through it or amps. That's why many suggest changing from an ammeter to a voltmeter when changing to an alternator. An alternator charges at a much higher rate than a generator and most ammeters are not designed to handle the increased charge rate and could be a fire hazard. A voltmeter is like a pressure gauge monitoring the pressure or volts. it just monitors. Nothing is passing through it.
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Posted By: captaindana
Date Posted: 14 Jan 2023 at 7:45am
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Holy Moley SUCCESS. FINISHED UP (for the 4th time) wiring and she charges nicely! WF thanks for the great understandable explanation! Steve as always thanks for the diagram and explains🤣! Thanks Dave and Dave and Aaron, Now I’ll roll her out of the warm shop (new to me) and drive in the next victim. 😮Thanks! Dana ------------- Blue Skies and Tail Winds Dana |
Posted By: steve(ill)
Date Posted: 14 Jan 2023 at 6:01pm
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I think it is very common mistake to remove the old AMP meter and install a VOLT meter with the same wires.... As WF said, that dont work... but common mistake. ------------- Like them all, but love the "B"s. |