TRACTOR PARTS Allis Chalmers Case & David Brown Farmall & International Ferguson Ford & New Holland John Deere Massey Ferguson Massey Harris Minneapolis Moline Oliver & Cockshutt Kubota / Yanmar

TRACTOR MANUALS

Allis Chalmers	Case	Farmall IH	Ford 8N,9N,2N	Ford
Ferguson	John Deere	Massey Ferguson	Minn. Moline	Oliver

Ford 9N, 2N & 8N Discussion Forum

Order Ford 8N Parts Online

resistor voltage on 8N

Welcome Guest, Log in or Register

Author

Barry8n

09-29-2004 12:26:31

Report to Moderator

I only have 1.5 volts on the coil side of the resistor, it shouldn't be that low I know. What should voltage be, it drops to 1.46 at coil.It has a little over 6 volts on switch side. The resistor looks like the original. Can I buy a replacement or should I go with a later version?
Oh, 49 8N with front mount distributor. What is the best way to check a front mount coil besides checking spark by arcing spark plug wires?

[Log in to Reply] [No Email]

Dell (WA)

09-30-2004 08:34:46

Report to Moderator

Re: resistor voltage on 8N in reply to Barry8N, 09-29-2004 15:00:12

Barry..... ...the primary resistance of the 6 volt squarecan frontmount ignition coil is about 1-ohm. It takes lab grade instruments to verify the typical squarecan primary winding shorts. That is why the "calibrated spark-gap" tester is so much better than an ohmmeter test. And that is also why even a cheep-o voltmeter measureing the 1-terminal voltage 3.2 volts (2.5 min, 3.5 max) with the points closed is more accurate than measuring the primary resistance. Its a technical thing..... ...Dell, former Calibration Lab Technician

[Log in to Reply] [No Email]

Rob

09-29-2004 13:43:52

Report to Moderator

Gotta clean up the wires and posts. in reply to Barry8n, 09-29-2004 12:26:31

Clean, bright and tight between the switch (6V) and backside of resister (1.5v). You'll get another volt or two. Repair or replace the wire if it's damaged or corroded. Don't put a piece of romex in there either. Stranded (not 7-strand) wire with crimp connectors.

[Log in to Reply] [No Email]

Dell (WA)

09-29-2004 13:26:58

Report to Moderator

Re: resistor voltage on 8N in reply to Barry8n, 09-29-2004 12:26:31

Barry..... ....thats the ONLY WAY for a shadetree mechanic to check enny sparkie coil. Check the sparkjumping ablility. Make a "calibrated" sparkie tester by taking enny old sparkie and gently bend the side electrode out for a 3/16" gap. Clamp the metal shell to any grounding bracket and plug any sparkie wire to the top of the test sparkie. Then while cranking the engine, watch the sparkies jump your calibrated sparkie tester. Do the sparkies jump the gap with blue-snott authority? Iff'n not, you gotts sparkie problems. Start with yer points first ($3, cheap), then iff'n that don't fix yer weak sparkies, next step should be intuitively obvious. Replace your ignition coil..... ..... respectfully, Dell

[Log in to Reply] [No Email]

souNdguy

09-29-2004 12:34:42

Report to Moderator

Re: resistor voltage on 8N in reply to Barry8n, 09-29-2004 12:26:31

Voltage at the top of the coil should be min 2.5 max 3.5 with 3 being pretty good... these are 'points closed'. Points open would be battery volts.

You might have poor wireing, and bad electrical connections, including your key switch.

Resistors usually fail 'open'.. not short.. so your resistor is most likely ok. .though the contacts for wire hookup could be dirty/coroded.

Do a quick test. run a good 14awg or better jumper wire from the battery to your disconnected and cleaned resistor, to your key switch, and to the coil. measure voltages.. now bypass the key switch by twisting the newends of your jumper wires over. Take another reading.

This should help you isolate the bad conenctions/wires.

The ballast resistor is still available at many online parts houses.. like here.. and at the nh dealership probably ( possibly? ).

Make a diagram before you start disconencting wires.

If it is a wireing problem.. TSC sells a good el-cheapo wire harness.

Soundguy

[Log in to Reply] [No Email]

[Options] [Printer Friendly] [Posting Help] [Return to Forum] [Log in to Reply]

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. [ About Us ]

Home | Forums

Copyright © 1997-2023 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