(800) 853-2651
SHOP NOW

Light switch charge resistor ohns ????

Crazy Horse

Crazy Horse

Well-known Member
In the old tractor light switches that are used also as a 3rd-brush generator charge control (low-high)on a 6V system, I'm wondering if my measurement of about 10 ohms of resistance (in the first or controlled position on the light switch) through the resistor is correct? I have a number of newer ceramic-insulated resistors to choose from to replace the original mica-cored wire resistor winding).
 
This has been discussed many times and I have participated in a number of the discussions, but I am drawing a COMPLETE blank at the moment as to what the Ohms value (and power dissipation rating) of the original resistors was. Got an old one to measure?

TRY your 10 Ohm unit and see what the generator charges, then adjust the chosen value up or down, as needed. You will NOT hurt the generator by experimenting a little!

I am guessing there will be MORE heating of the resistor than you may expect, so have a plan to mount it securely and keep wiring in the panel from contacting it.
 
If it"s an odd jobs putting around tractor used for an hour or two and not in extreme heat. Forget about the resistor and wire direct.
 
Based on a few old ones I observed over the years (but memory is rusty grrrrr) and a very rough approximation of genny field current and to reduce it to maybe 1/2 or more of what full field current might be,

I guess 2.5 TO 4 OHMS is closer then 10 ohms, I'm afraid a 10 ohm resistor would lower the field current and charge rate wayyyyy too much.

Buy hey, no harm in trying 10 as you can always decrease the resistance as needed, but I think you will end up quite a bit less ohms to reduce the charge rate to maybe 1/2 to 3/4 as much as if on high charge i.e. no added field resistance.....

Dont forget that needs to be a power rated resistor P=ExI remember

Give 10 ohms a try, no harm no foul other then the output will be way too low......

John T
 
You must log in or register to reply here.

Similar threads

S
Ford 860 wont start/run suddenly
2
Replies
23
Views
2K
docmirror
D
Crazy Horse
Generator and regulator type A or B match ???
Replies
11
Views
2K
JMOR
J
T
FORD TRACTORS - ELECTRICAL SYSTEMS 101
Replies
7
Views
2K
used red MN
U
C
Charging system on 1950 Allis Chalmers CA
Replies
7
Views
893
Janicholson
Janicholson
R
WD45 Light Switch Options
Replies
5
Views
745
4wdtom
4
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