Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

Discussion Forum
:

Jd starter

Welcome Guest, Log in or Register
Author 
david

05-02-2002 18:40:18




Report to Moderator

On a jd 50, there is a small wire terminal on the starter switch that is only hot when the starter is engaged.The wire goes directly to the coil.Is this to give a full 12 volts to the coil for easier starting. Older models ( 6 volt ) dont have this. Please explain. Thanks. David




[Log in to Reply]   [No Email]
Clooney

05-02-2002 19:11:12




Report to Moderator
 Re: jd starter in reply to david, 05-02-2002 18:40:18  
David, it's called "by-pass" starting. ~Some, but not all 12 volt ignition systems use a 6 volt coil with a resistor between the ignition switch & coil to lower the 12-14 volts in the system to 6-8 volts to power the coil. The main reason for using a 6 volt coil on a 12 volt system is to allow the coil to receive 11 or so volts during cranking to produce a hotter spark for easier & faster starts. ~On your 50 there is a second contact on the starter switch that hooks to the coil [power side] & by-passes the resistor during cranking to feed 11 or so volts to the 6 volt coil during cranking, once the starter switch is opened & the starter quits, the coil is powered through the resistor & the coil receives 6-8 volts for continuous running.
~On point equipped 12 volt ignition systems the points can only carry a reasonable amount of current without burning & a 6 volt coil has very low resistance that passes more current than a set of points can safely handle, so the resistor is needed. ~On a 6 volt system with a 6 volt coil, the coil has the same low resistance but the initial voltage is lower so the current to the points is under the point damage threshold. The problem with a 6 volt system is the coil only receives about 5 volts during cranking & that is barely adequate to produce a decent spark. Any extra resistance in a 6 volt system due to old wiring, poor contact of connections, oxidation or low battery leaves the coil with even less voltage during cranking & sometimes a no-start condition due to poor spark. You can see how a 6 volt coil operating at 11 volts was quite a help in the starting department.....

[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

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

Website Accessibility Policy