Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

12 v conversion

Goto page Previous  1, 2

Post new topic    
View previous topic :: View next topic  
Author Message
Long Time User

Joined: 23 May 2017
Posts: 868

Report to Moderator

PostPosted: Wed Dec 06, 2017 6:46 pm    Post subject: Re: 12 v conversion Reply to specific post Reply with quote

Yes, the condensers are the same on 6 or 12V systems, but they need to be rated at much higher voltages than that. If you look at an old automotive oscilloscope in action, the primary spikes will run around 30V on a healthy system. One with an open (or disconnected) plug wire or even just a wide plug gap can easily exceed 50V. An ignition condenser should be rated 100V or better, but I doubt most of the ones you buy today are. Certainly the days of leaving the condenser in for 50,000 miles are over.
Back to top
View user's profile

Joined: 26 Nov 2017
Posts: 65

Report to Moderator

PostPosted: Wed Dec 06, 2017 9:08 pm    Post subject: Re: 12 v conversion Reply to specific post Reply with quote

Thanks so much, this explination was very helpful

quote="CVPost-rvirgil_KS"](quoted from post at 10:17:26 12/05/17) There are 2 types of coils labeled for 12 volts. One is labeled ?12 volts use external resistor? and the other labeled ?12 volts, no external resistor required?. The first has about 1 1/2 ohms resistance across + an ? terminals of the coil, the second has about 3 ohms. The difference is in the wire used to wind the coils, there is no added resistor in series with the coil inside the can. You could use the ?external resistor required? coil on a 6 volt system and eliminate the resistor.

The purpose of the resistance is to limit current through points and coil to about 4 amps. With the external resistor limiting the current it divides the supply voltage across coil and resistor so you see 6 volts dropped across each one.

With positive ground the + terminal should go to the side of distributor, with negative ground the ? goes to distributor. The coil doesn?t care which way it is wired, the difference has to do with the spark plug. If the coil is wired to match battery polarity the plug will ?spit? the spark from center electrode to ground tab. If coil polarity is reversed the plug will ?suck? the spark from ground tab to center electrode. The plug is more efficient if it ?spits? rather than ?sucks? the spark.

There is no distinction between a 6 volt and 12 volt condenser. If you could find specs on a condenser you would find they are actually rated for several hundred volts.

If you understand a 6 volt system, you understand a 12 volt system. They work the same. Difference is in amount of resistance in circuit to limit coil/points current.

Positive or negative ground is like right hand or left hand threads on a bolt. With bolts the nuts turn in opposite directions, with battery system current flows in opposite directions. Positive or negative ground should work equally well if polarity sensitive components such as ammeter, coil, and charging system are all configured to match battery polarity.

Make sure you have good quality battery cables and connections on both ends of both cables are clean and tight.[/quote]
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Case and David Brown All times are GMT - 8 Hours
Goto page Previous  1, 2
Page 2 of 2

Jump to:  

Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters