Yesterday's Tractor Co. Parts for Farm Tractors - Compare our Prices!
Click Here or call 800-853-2651 
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

8n pulling 30 amps at 1/2 throttle no load


 
Post new topic    
View previous topic :: View next topic  
Author Message
ToddNick
New User


Joined: 29 Oct 2012
Posts: 5


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:13 pm    Post subject: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

Guys,

I have been reading your posts for awhile to help me get my 8n 6v side mount running, but now I am needing help.

My ammeter shows 30'plus at mid throttle in neutral. I began with a neg read with lights on engine off and no amps when running. I followed the diagnostic chart and jumped the bat and arm with it running and it jumped to 30 so I replaced the vr. The new vr is now showing neg amps with lights on and engine off but showing around 10 amps at idle and 30 when mid throttle. I removed the field from the gen and it immediately dropped to zero amps when running. I jumped the filed from gen to field on vr and right back to 30. Is my gen bad? Or is my new vr playing games? I did polarize after replacing the vr.
 
Back to top
View user's profile
JMOR
Tractor Guru


Joined: 13 Aug 2007
Posts: 15099


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:17 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

ToddNick wrote:
(quoted from post at 20:13:31 10/29/12) Guys,

I have been reading your posts for awhile to help me get my 8n 6v side mount running, but now I am needing help.

My ammeter shows 30'plus at mid throttle in neutral. I began with a neg read with lights on engine off and no amps when running. I followed the diagnostic chart and jumped the bat and arm with it running and it jumped to 30 so I replaced the vr. The new vr is now showing neg amps with lights on and engine off but showing around 10 amps at idle and 30 when mid throttle. I removed the field from the gen and it immediately dropped to zero amps when running. I jumped the filed from gen to field on vr and right back to 30. Is my gen bad? Or is my new vr playing games? I did polarize after replacing the vr.
Gen to Fld jumper should have & probably did weld the field control contacts together such that it will put out full charge all the time, & eventually boil the battery.
 
Back to top
View user's profile
ToddNick
New User


Joined: 29 Oct 2012
Posts: 5


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:29 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

Fld from gen goes to fld on vr, right? So I removed them both
and used a dedicated jumper to rule out a bad wire and got the
same result.
 
Back to top
View user's profile
JMOR
Tractor Guru


Joined: 13 Aug 2007
Posts: 15099


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:40 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

ToddNick wrote:
(quoted from post at 20:29:44 10/29/12) Fld from gen goes to fld on vr, right? So I removed them both
and used a dedicated jumper to rule out a bad wire and got the
same result.
OK, my bad. I mis-read your sentence. Yes, gen field is a direct wire to VR field terminal. It does however sound like field contacts in VR are stuck closed, thus grounding the generator Field terminal all the time & that yields full field current & max gen output. BUT, a bad or even undercharged battery will have a low enough voltage to cause the field control to call for full charge until battery voltage rises to a level that VR senses that voltage & starts to reduce field current. Can you get a good battery voltage measurement both before starting and after/while running at 30amps?
 
Back to top
View user's profile
ToddNick
New User


Joined: 29 Oct 2012
Posts: 5


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:50 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

Battery shows 6.08 standing (post to post) and climbed to 7.3
after running mid throttle for a few minutes.
 
Back to top
View user's profile
JMOR
Tractor Guru


Joined: 13 Aug 2007
Posts: 15099


Report to Moderator

PostPosted: Mon Oct 29, 2012 4:57 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

ToddNick wrote:
(quoted from post at 20:50:40 10/29/12) Battery shows 6.08 standing (post to post) and climbed to 7.3
after running mid throttle for a few minutes.
According to Ford spec sheet @ 20amps, 6.8v should command a reduction.
At 5amps, it can reach 7.4v before reducing output.

But you are at 30A and 7.3v & that is out of spec.

I would remove reg cover & feel to see if you can open field contacts against spring force or if they are stuck closed.
 
Back to top
View user's profile
ToddNick
New User


Joined: 29 Oct 2012
Posts: 5


Report to Moderator

PostPosted: Mon Oct 29, 2012 5:19 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

I actually did that earlier this evening. Both contacts in the VR
appeared free.
 
Back to top
View user's profile
JMOR
Tractor Guru


Joined: 13 Aug 2007
Posts: 15099


Report to Moderator

PostPosted: Mon Oct 29, 2012 5:48 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

ToddNick wrote:
(quoted from post at 21:19:38 10/29/12) I actually did that earlier this evening. Both contacts in the VR
appeared free.
If field control contacts are not opening at spec voltage, then it is possible that the shunt coil that senses the voltage & pulls them open has an open wire/winding in it. Be sure the ground wire between VR case and generator case is good.
 
Back to top
View user's profile
souNdguy
Tractor Guru


Joined: 20 Aug 2002
Posts: 53220


Report to Moderator

PostPosted: Tue Oct 30, 2012 5:28 am    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

just to recap. if the vreg field contacts are propped open with a toothpic does the charge drop?

if yes, and the field contacts are jsut ataying closed full time.. then the vreg is bad.
 
Back to top
View user's profile
ZANE
Tractor Guru


Joined: 10 Aug 1998
Posts: 10262


Report to Moderator

PostPosted: Tue Oct 30, 2012 12:26 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

I'm just asking, but aren't there two different VRs for the 8Ns at different serial numbers????

Which one should he have?

Zane
 
Back to top
View user's profile
ToddNick
New User


Joined: 29 Oct 2012
Posts: 5


Report to Moderator

PostPosted: Tue Oct 30, 2012 12:27 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

Yea, the voltage dropped to zero when I propped the field contact open with a toothpick. Nice trick.

I will get another new VR and see if that fixes it. Stupid question- Can the gap be set on the field contacts?

I appreciate the knowledge you folks have in regards to these old gems.
 
Back to top
View user's profile
souNdguy
Tractor Guru


Joined: 20 Aug 2002
Posts: 53220


Report to Moderator

PostPosted: Tue Oct 30, 2012 1:18 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

sometimes you can find an adjustable field and cutout reg.. most of the itme adjustment is by tweaking / bending.

in your case.. field ckt may actually be dead, and thus not operating the field contacts at all.. just leaving them closed..
 
Back to top
View user's profile
JMOR
Tractor Guru


Joined: 13 Aug 2007
Posts: 15099


Report to Moderator

PostPosted: Tue Oct 30, 2012 1:29 pm    Post subject: Re: 8n pulling 30 amps at 1/2 throttle no load Reply to specific post Reply with quote

ZANE wrote:
(quoted from post at 16:26:50 10/30/12) I'm just asking, but aren't there two different VRs for the 8Ns at different serial numbers????

Which one should he have?

Zane
Yes, Zane, but the 8N10505A is unobtainium these days, so you just have to use the 8N10505B and set the 3rd brush to limit current.
See my long answer at link, near bottom of first page of threads in modern view.
http://ytforums.ytmag.com/viewtopic.php?t=956884
 
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Ford 9N, 2N, 8N All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
TRACTOR   PARTS TRACTOR   MANUALS
Same-Day Shipping! Most of our stocked parts ship the same day you order (M-F).  Expedited shipping available, just call!  Most prices for parts and manuals are below our competitors.  Compare our super low shipping rates!  We have the parts you need to repair your tractor.  We are a Company you can trust and have generous return policies!   Shop Online Today or call our friendly sales staff toll free (800) 853-2651.

YT Home  |  Forums Home

Copyright © 1997-2014 Yesterday's Tractor Co.

Powered by phpBB © 2001, 2005 phpBB Group

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