Posted by John T on July 31, 2017 at 13:41:23 from (216.249.81.101):
In Reply to: no spark posted by newhaven on July 31, 2017 at 04:43:17:
On that 12 volt tractor you can use EITHER:
a) A full 12 volt rated coil no ballast required. It may be labeled "12 Volts" OR "12 Volts not for use with ballast resistor" They are readily available at NAPA or Tractor Supply or Rural King. It will have a Low Voltage LV primary resistance of around 2.5 to 3.5 or so ohms (many are 3 ohms).
b) A 6 Volt rated coil PLUS an external series voltage dropping (12 down to 6) ballast resistor. It will have a LV primary resistance of around 1.2 to 1.8 ohms (many are 1.5 ohms). Many typical common old tractor ballast resistors are around 1.2 to 1.8 ohms SUBJECT TO the LV primary resistance of the coil they are used with. If its a 12 volt tractor and you use a 6 volt coil in order to get a 50 50 voltage divider so 6 volts are dropped across the resistor leaving 6 volts for a 6 volt rated coil, the coils LV primary resistance and the ballast resistance is close to the same IE 1.2 to 1.8 or so ohms each.
NOTE since this is an old farm tractor forum and NOT an old car forum, I'm talking about typical old farm tractor 6 and 12 volt coils and the ballast resistors they used. Still FYI some 12 volt US made cars and trucks used 12 volt coils while some used 6 volt coils plus an external ballast resistor.
I would use a full 12 volt rated coil no ballast required for simpler wiring. Many old farm tractors that were 12 volt still used a 6 volt coil PLUS an external ballast PLUS a start ballast by pass system to improve cold weather starting.
NOW if theres no fire if you work through my Ignition Troubleshooting procedure it can help find the cause. Its simple and easy step by step and no fancy tools are required
Upload one or more videos to your post. Photo filesizes should be less than 300K and Videos, less than 2MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
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 ]
Today's Featured Article - A Cautionary Tale - by Ian Minshull. In the early 1950s my father bought an Allis Chalmers B and I used it for all the row crop work with the mangolds and potatoes, rolling and the haymaking on our farm. The farm and the Allis were sold and I have spent a lifetime working on farms throughout the country. I promised myself that one day I would own an Allis. That time event
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
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.
