Farmall & IHC Tractors Discussion Board |
Re: Ignition System Problems
[ Expand ] [ View Replies ] [ Add a Reply ] [ Return to Forum ]
Posted by John T on October 25, 2006 at 07:18:33 from (66.244.90.5):
In Reply to: Ignition System Problems posted by Larry Schmitendorf on October 24, 2006 at 20:33:34:
Larry, Those coils labeled "12 volts for use with (or requires) an external ballast resistor" are in reality 6 volts coils and indeed on 12 volt tractors one is required or the coil will run too hot and the points burn up prematurely. That being said, the next question is WHAT OHMS BALLAST should be used????? It should generally be near the same ohms as the coils primary (measured between its lil + and - terminals) so a 50/50 12/6 voltage divider is formed. Typical of ballast ohms and 6 volt coil primary ohms would be maybe 1.25 to 2 ohms but iffffffff the ballast is wayyyyyyyyy higher in ohms then the coils primary, a low ignition current and resultant weak spark (especially when cranking) can happen!!!!! BOTTOM LINE you need the correct sized ohms ballast to match the coils primary winding resistance and most Ive seen are in the 1.5 to 1.85 or so ohms range ifffffffff designed for the old point n condensor ignition systems having coils of the primary resistance mentioned above. NEXT thing I would suspect is a bad/resistive ignition switch which a simple "hot wire" test will answer. Simply by pass eliminate the ignition switch by running a jumper wire direct from the hot ungrounded battery post to the high input (NOT to coil) side of the ballast n see what happens then??????????? if that cures the problem suspect the switch. With the ignition on and the points closed (if all else is okay) when using a 6 volt coil and an external ballast on a 12 volt tractor there should be near 6 volts on the coils input but if its wayyyyy less suspect a bad switch or the ballast is tooooooo high ohms. FINALLY I like Olds suggestion,,,,,, A weak battery and/or a weak starter can cause excess voltage drop while cranking which causes a weak spark which by passing the ballast could help (as a band aid approach). Have the battery load tested and if it and the cables n starter switch/solenoid are all okay but theres excess voltage drop on the battery while cranking, the starer could be the problem BUTTTTTTT FIRST I would remove, clean n wire brush, n reattch each n every battery n starter switch/solenoid n starter n ground cable conenction cuz a bad cable or connection can cause voltage drop and a weak starting spark TRY THAT FIRST !!!!!!!!!!!! John T
Replies:
Home
| Forums
Today's Featured Article -
Tractor Profile: Farmall M - by Staff. H so that mountable implements were interchaneable. The Farmall M was most popular with large-acreage row-crop farmers. It was powered by either a high-compression gas engine or a distillate version with lower compression. Options included the Lift-All hydraulic system, a belt pulley, PTO, rubber tires, starter, lights and a swinging drawbar. It could be ordered in the high-crop, wide-front or tricycle configurations. The high-crop version was called a Model MV.
... [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]
Copyright © 1997-2024 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 HeadquartersWebsite Accessibility Policy |
|