Wiring a CA for 12V
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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=33021
Printed Date: 28 Apr 2024 at 10:19pm
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Topic: Wiring a CA for 12V
Posted By: Nat
Subject: Wiring a CA for 12V
Date Posted: 28 Jun 2011 at 6:57pm
| I'm rewiring an old CA that I bought. It was 6V but didn't charge, so it is easier and cheaper on me to convert to 12 V. I already have a good 12V Battery and a good single wire altenator and there is no lights so it will be a pretty strait-foward job. My question to you guys is how anyone else has done it. I am planning on running the single wire from the alt to the amp guage then to the battery. Has anyone had one set up differently and how does it work? Any help will be appreciated, Thanks, nat |
Replies:
Posted By: Steve in NJ
Date Posted: 28 Jun 2011 at 8:28pm
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First of all, one wire Alternators do not work well with early Tractors. Most one wire units need 1200-1400 rpm to excite the VR to charge. That means you rev the snot out of the engine to get it to charge. Tough on the engine. Change it to a 3 wire, where the Alt starts charging as soon as the engine starts. Most one wires can be changed to 3 wires. Second- Alternator's, (especially one wires) should not be directly wired to the Battery. When the Tractor sits, the one wire Alt will draw on the Battery, eventually draining it. Third- Alternators should not be used with Ammeters. Especially a 20/20 sweep OEM Ammeter. Use a Voltmeter in lieu of the Ammeter. Its safer. If you insist on using an Ammeter, use a 60/60 sweep unit, just in case a short develops on board somewhere and a king size draw occurs. That Alternator will smoke that 20/20 sweep Ammeter in a heart beat! Lastly, CA's are usually Distributor fired. With 12V's, you need to establish 2.7-3.3 ohms of resistance in the Ignition circuit. You need to change the coil over to a 3.0 ohm coil with the 4 cylinder, and use an Ignition key to control power on board the Tractor to the Ignition. Don't forget to change the wiring around to Neg. ground. That means the - Neg side of the coil goes to the Distributor. OR you can purchase a wiring only kit from us (less the Alt) which gives you everything needed to wire the Tractor safely along with step by step instructions and color coded CAD wiring diagram. If you're gonna wire it yourself, do it the correct way. This way it makes the Tractor reliable, as well as safe... HTH Steve@B&B |
Posted By: Gerald J.
Date Posted: 28 Jun 2011 at 8:43pm
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And you need to reverse the connections at the ammeter when putting in one sturdy enough to survive the alternator. Gerald J. |
Posted By: wfmurray
Date Posted: 28 Jun 2011 at 8:47pm
| Put 12 volt on my B .It would not rev enough to charge . Run wire from alterator to dash to make it excite. Put a toggle switch on mine ,shiould have used push button. Crank flip switch on and back off, will charge untill motor stops.Will run battery down if you leave switch on , reason for push button . Over two years and no problem. |
Posted By: Jeff Z. NY
Date Posted: 28 Jun 2011 at 8:54pm
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Buy a single wire that has been reworked to exite at low speeds and get the small pulley for it.
I have two and both work and charge fine on my B's and they have very low drain on the battery. You should really have a battery disconnect switch on the tractor already for safety. Just turn off the battery when you park it and that's that. If you want more info send a PM. |
Posted By: wkpoor
Date Posted: 28 Jun 2011 at 10:34pm
| I'll throw a twist in here. If you don't have lights then you really don't need a charging system IMO. Especially if you go to 12v. It will start your tractor maybe 50-100xs before it needs charged. Or like I do I just convert everything I own to mag and be done with the wires all together. I really don't like the alt conversions and would rather see a 12v genny. Personally I think the original 6v gen was perfectly adequate and I am very surprised at how bright my one CA is with the original bulbs. |
Posted By: GregLawlerMinn
Date Posted: 29 Jun 2011 at 5:09am
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Agree with Bill, one can start and run a tractor for a long time without a generator or alternator by manually charging the battery periodocally (been there, done that). That said, I upgrade my 6V tractors to 12V because parts (wiring, bulbs, gages, batteries are readily available). I like using a 12V old Chevy generator (the short one) for my 12V upgrades. Cost is about the same as an alternator, bolts right in the 6V gennie mounts, and looks like the original. I mount the VR inside the tool box to keep it out of the weather.And finally, I install an EI module. Then I have an electrical system that is reliable and does not require as much maintenance as the 6V systems ------------- What this country needs is more unemployed politicians-and lawyers. Currently have: 1 D14 and a D15S2. With new owners: 2Bs,9CAs,1WD,2 D12s,5D14s,3D15S2s, 2D17SIVs,D17D,1D19D;1 Unstyled WC |
Posted By: Bee
Date Posted: 29 Jun 2011 at 7:17am
------------- Bob, North Carolina 1949 B |
Posted By: Rich Steiner
Date Posted: 29 Jun 2011 at 8:28am
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Thanks Fellas.... I'm going to use this on my CA I need to get a charging system for one of my CA's and this looks like the way to go. Rich PS. I decided to leave my wide front CA on 6 volt positive ground....
|
Posted By: Nat
Date Posted: 29 Jun 2011 at 11:44am
| I really appreciate all the help. I may rethink the single wire alt theroy and go a different route. Thanks again, Nat |
Posted By: Gerald J.
Date Posted: 29 Jun 2011 at 3:05pm
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The pushbutton charging switch works. Also running the alternator from the ignition circuit works, the accessory terminal on the switch (probably not present on the original switch, but common on universal ignition switches) and is good. Running from the ignition circuit requires either a diode, a lamp, or a resistor in the lead to the alternator else the alternator will back feed power and the engine won't stop when you turn the ignition switch off. Gerald J. |
Posted By: Nat
Date Posted: 29 Jun 2011 at 7:24pm
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Gerald, are you saying that is the switch has the acc position you don't need the diode or a lamp? My switch has 3 positions, the center is off, to the left is run and to the right is run and lights. It seems from your post that I don't need a lamp or diode, is this correct? Thanks, nat ------------- Nat |
Posted By: Gerald J.
Date Posted: 29 Jun 2011 at 9:04pm
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That's right. The accessory post is only connected in the accessary and the run positions, not the start or off positions. That's on a universal car switch. On your switch hook the alternator to the lights and switch to lights to start the alternator. Or wire with diode or light or resistor to the ignition circuit. Gerald J. |