(800) 853-2651
SHOP NOW

12volt resistor

A

Anonymous-0

Well-known Member
What would happen if someone switched a tractor from 6volt to 12volt and did not use a resistor on the coil? The reason iam asking is the old man down the road from me has a farmall H. Someone put a 12v alternator on it but i dont see any ceramic resistor by the coil.It looks like the original 6volt IH coil on it.
 
It will run, but point life and current in the primary will be excessive. With small wire, and good luck it could last a while.
The coils are pretty tough, and if it was not run for hours on end as it might have been when new, it could be OK. Jim
 
To add to what Jim said if the ignition switch is left on for say 5 plus minutes with out the engine running the coil can/will explode and make a mess of things. Also the life of the coil will be a lot shorter
 
I've seen a 6 volt coil overheat and split after being fed 12 volts for a couple hours. And like Jim states it also rapidly wears (burns out) the breaker points.
 
I agree with the gents below: Ive seen nasty lookin sticky black "stuff" ooze out of them, probably not recommended and the EPA may throw the owner in jail. They also emit a nasty burn smell and the coil will most likely eventually totally fail if the points last long enough. They can get so hot you cant hold your hand on them..

I believe if its a 6 volt coil Id be adding that external series voltage dropping (12 to 6) current reducing (8 to 4) ballast resistor pretty quick.

John T
 
With the sw on what does a volt meter read. Check the coil it mite have been changed to a 12v one as they do make them.
 
Have to agree with John T. If it is a 6 volt coil then a ballast resistor should be fitted straight away. Otherwise, fit a 12 volt coil. If it has an alternator, originality is presumably not a major concern?
SadFarmall
 
You must log in or register to reply here.

Similar threads

F
Scratching My Head On This Farmall H Ignition System
Replies
9
Views
457
Farm Boys Way
F
K
How to rewire fuel pump when removing external resistor
Replies
1
Views
173
BarnyardEngineering
BarnyardEngineering
K
How to rewire fuel pump when removing external resistor
Replies
13
Views
494
used red MN
U
R
49 8n ignition resistor burning up
2
Replies
33
Views
1K
RRSPRINGS
R
P
300 U 12Volt conversion pulley question
Replies
10
Views
376
charlieu
C
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.

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 Headquarters
Website Accessibility Policy

Back
Top