Coil resistor

All other non-specific model Farmall / IH / CASE tractors. (Catch-All)

Moderator: Team Cub

Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
ScottyD'sdad
Cub Pro
Cub Pro
501 Club
501 Club
Posts: 6152
Joined: Thu Aug 31, 2006 7:00 pm
Zip Code: 02769
Tractors Owned: 6"F" cubs
5 lo-boys
1 154
1 184
1 IH444
1 Oliver OC3 crawler
1 AC D10
1 IH 100 manure spreader
1 IH model B corn grinder
3 power units
cub demonstrator
Circle of Safety: Y
Location: Ma. Rehoboth

Coil resistor

Postby ScottyD'sdad » Fri Apr 20, 2012 12:46 pm

My neighbor's 424 died, and had no spark. He replaced the coil, with no success. I changed the points and condenser, still no luck. We bypassed the coil resistor, and its running fine. 12 volt system, 12 volt coil, what is the purpose of the resistor, and can we eliminate it? Coil didn't heat up, with the resistor bypassed. Ed
Image
Member of Chapter 18, and National club

DanR
5+ Years
5+ Years
501 Club
501 Club
Posts: 1631
Joined: Fri Dec 22, 2006 6:28 am
Zip Code: 37743
Circle of Safety: Y
Location: Tennessee East

Re: Coil resistor

Postby DanR » Fri Apr 20, 2012 1:02 pm

It sounds like the original 6v coil was replaced with a 12v one . Since the tractor is 12v there is no need for a resistor to drop 12v to 6v.
47 Cub (Glenda)
52 Super A
62 Cub (Genie)
43 H
42 M
In all things know which way the wind is blowing.

ScottyD'sdad
Cub Pro
Cub Pro
501 Club
501 Club
Posts: 6152
Joined: Thu Aug 31, 2006 7:00 pm
Zip Code: 02769
Tractors Owned: 6"F" cubs
5 lo-boys
1 154
1 184
1 IH444
1 Oliver OC3 crawler
1 AC D10
1 IH 100 manure spreader
1 IH model B corn grinder
3 power units
cub demonstrator
Circle of Safety: Y
Location: Ma. Rehoboth

Re: Coil resistor

Postby ScottyD'sdad » Fri Apr 20, 2012 3:57 pm

DanR wrote:It sounds like the original 6v coil was replaced with a 12v one . Since the tractor is 12v there is no need for a resistor to drop 12v to 6v.

Thats what I thought, but wanted a second opinion. Thanks, Ed
Image
Member of Chapter 18, and National club

User avatar
John *.?-!.* cub owner
Team Cub Guide
Team Cub Guide
501 Club
501 Club
Posts: 21531
Joined: Sun Feb 02, 2003 2:09 pm
Zip Code: 63664
Tractors Owned: 47, 48, 49 cub plus Wagner loader & other attachments. 41 Farmall H.
Location: Mo, Potosi

Re: Coil resistor

Postby John *.?-!.* cub owner » Fri Apr 20, 2012 4:32 pm

Make sure the coil says 12 volts, internal resister. Many say 12 volts external resister. The ones that say external resister will run without it fr quite a while but will fail much sooner than with it.
If you are not part of the solution,
you are part of the problem!!!

User avatar
BIGHOSS
10+ Years
10+ Years
501 Club
501 Club
Posts: 1540
Joined: Tue Jul 18, 2006 9:55 pm
Zip Code: 37087
Tractors Owned: 1947 Cub S/N 9216
w/ C-22 Mower

1974 Cub S/N 244814
w/59 Woods Mower

Ford 3000 Gas S/N C375091 w/Bushhog QT2345 Loader & 6' Squealer Bushhog
Circle of Safety: Y
Location: TN, Lebanon

Re: Coil resistor

Postby BIGHOSS » Fri Apr 20, 2012 6:10 pm

I have always had the understanding that a resistor, whether internal or external, is necessary between coil and points to prevent points from burning. Start on full voltage and run on a lesser voltage.
We make a living by what we get, but we make a life by what we give......Winston Churchill

User avatar
John *.?-!.* cub owner
Team Cub Guide
Team Cub Guide
501 Club
501 Club
Posts: 21531
Joined: Sun Feb 02, 2003 2:09 pm
Zip Code: 63664
Tractors Owned: 47, 48, 49 cub plus Wagner loader & other attachments. 41 Farmall H.
Location: Mo, Potosi

Re: Coil resistor

Postby John *.?-!.* cub owner » Fri Apr 20, 2012 6:58 pm

To start on full voltage and run on lessor voltage you would need an extra lead from starter relay that bypasses the resister. a resister provides the same drop all the time.
If you are not part of the solution,
you are part of the problem!!!

User avatar
artc
Cub Pro
Cub Pro
501 Club
501 Club
Posts: 1840
Joined: Sun Mar 30, 2003 10:25 am
Zip Code: 06457
eBay ID: cmtelephone
Tractors Owned: 1950 cubs (3), 1948 cub, 1941 A, 1948 H, 1963 B414, 1958 240U, 1947 Oliver 60 industrial, Oliver 70 industrial.1948 super AI (trailer queen), 1958 450.
Location: CT, Middletown

Re: Coil resistor

Postby artc » Wed Aug 01, 2012 11:22 am

to add to what John said, a resister is needed in the circuit - either internally in the coil, or externally in the form of the big white resister. Automobiles in the 60's (12 volt) used a start circuit that connected 12 volts to the coil for starting, then went to the resister setup when you released the key to the run position. on Chrysler and IH vehicles that was done with the resister. on GM products, it was done with a resister wire to the coil. Fords i dont recall but i'm thinking resister.
if you burned out a resister, the engine would start and then die as you released the key. running for an extensive period of time with the resister bypassed will result in burnt points and coil overheating.

a 6 volt coil is just fine on 12 volts with the resister in place.
'If they're tappin', they're not burnin'
http://www.ZagrayFarmMuseum.org


Return to “Farmall / IH / CASE”

Who is online

Users browsing this forum: No registered users and 0 guests