Yesterday's Tractor Co.
Shop Now View Cart
   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 inLog in 

Replacement wiring harness


 
Post new topic    
View previous topic :: View next topic  
Author Message
modirt
Regular


Joined: 17 Nov 2018
Posts: 235


Report to Moderator

PostPosted: Tue Jul 02, 2019 6:12 am    Post subject: Replacement wiring harness Reply to specific post Reply with quote

Looks like two concurrent questions on a related topic. You guys were a huge help with my exhaust question, so will try you out on this too.

I'm replacing the existing wiring harness on a piece of equipment with the 318 Chrysler. Existing wires are about 50 years old, with numerous breaks and splices. So to eliminate problems, all new it is.

So this question is about the starter circuit. Beginning at the starter, a #10 wire goes over the same stud on the starter as the heavy wire from the battery. Lets call that wire A, which then runs forward to the starter switch. Starter switch has studs for Wire A; Wire B (a #10 starter output wire that runs to the voltmeter......through the voltmeter and back to the solenoid on the starter); a 3rd stud for the coil wire; and 4th stud for accessories.

At the voltmeter, Wire B is connected via the same stud to an additional #10 wire that runs to the alternator (lets call the wire to the alternator Wire C). I also found a 3rd wire under that volt meter stud that was the hot wire to a turn signal blinker switch. Basically treating it as if it were an accessory stud. This is the part that has me stumped.

The only time that circuit should be hot is when the starter switch is turned past "on" to "start". And why would it be connected back to the alternator? And if it was only a "start" circuit, how would the voltmeter work at all....except with the "start" switch was engaged? I can't imagine the old voltmeter itself being any type of "switch".....rather it should only be a metering device.

Alternator has it's own #10 wire running back to the battery. There is a voltage regulator mounted near the engine, but it is not connected to anything. I presume the alternator that is there now is a replacement and this replacement has it's own internal regulator, bypassing the need for an external voltage regulator?

So can anyone explain why the starter wire back to the solenoid would be run through the voltmeter and connected to the alternator?
 
Back to top
View user's profile
Steve@Advance
Tractor Guru


Joined: 12 Nov 2013
Posts: 14223


Report to Moderator

PostPosted: Tue Jul 02, 2019 12:06 pm    Post subject: Re: Replacement wiring harness Reply to specific post Reply with quote

Are you sure you are looking at the back of the volt meter and not the ignition switch?

I've never seen a volt meter or amp meter with more than 2 terminals.

If I substitute "ignition switch" for every where you referenced "volt meter" it kinda sorta makes sense.

And does it have a volt meter, or an amp meter? Makes a big difference in how things are wired. Most older equipment had an amp meter. Volt meters came along more recently.

It does sound like some wires may be out of place, a lot can happen to a piece of equipment over the years.

You might Google "Gas tractor wiring", look at some of the simple generic wiring diagrams. Also look at "10SI" alternator wiring. That's the most common alternator, or look at whatever brand and model you have, find the wiring diagram, overlay it with the generic diagram, that should give you an understanding of what you have.
 
Back to top
View user's profile
modirt
Regular


Joined: 17 Nov 2018
Posts: 235


Report to Moderator

PostPosted: Tue Jul 02, 2019 6:45 pm    Post subject: Re: Replacement wiring harness Reply to specific post Reply with quote

CVPost-Steve@Advance wrote:
(quoted from post at 13:06:33 07/02/19) Are you sure you are looking at the back of the volt meter and not the ignition switch?

I've never seen a volt meter or amp meter with more than 2 terminals.

If I substitute "ignition switch" for every where you referenced "volt meter" it kinda sorta makes sense.

And does it have a volt meter, or an amp meter? Makes a big difference in how things are wired. Most older equipment had an amp meter. Volt meters came along more recently.

It does sound like some wires may be out of place, a lot can happen to a piece of equipment over the years.

You might Google "Gas tractor wiring", look at some of the simple generic wiring diagrams. Also look at "10SI" alternator wiring. That's the most common alternator, or look at whatever brand and model you have, find the wiring diagram, overlay it with the generic diagram, that should give you an understanding of what you have.


Good call. It is an older amp meter (damaged from too much time in the sun) and it only has two terminals.

And I think I described the condition as found correctly. Wire leaves the starter, runs forward to the 4 way starter switch. Return wire off the middle stud on the starter switch ran to the amp meter, where it and another 10 gauge wire that runs to the alternator were connected to 1st stud.......and the wire back to the starter solenoid ran off the 2nd stud. The wire to the alternator makes no sense, so for now, I have bypassed the amp meter completely. Wire off the center stud of the starter switch now runs straight back to the starter solenoid.

Alternator already has it's own 10 gauge wire back to the + post on the battery, along with a jumper wire to the exciter, plus a 2nd wire spliced to the coil wire back to the exciter. To add that additional 10 gauge wire off the alternator forward to the same stud as the starting circuit wire makes no sense. In theory, starter wire circuit should only be hot when the starter switch is engaged. Adding the 2nd wire would have it back feeding at all times....or so it would seem.

BTW, machine was not running when I bought it, and this, along with a few other weird glitches may be why. We had no luck using it as it was, so for an engine test, just ran the two starter wires around the harness to the starter switch and to the coil and doing that, she fired right up.

Best plan may be to ignore everything as I found it and try to devise a typical wiring plan that works, which I'm in the process of doing. I'm finding a lot of wires that connect to various switches, then just end somewhere.

Machine is over 50 years old and has had multiple owners of unknown mechanical knowledge, so who knows what was original what has been jerry rigged.

Hope is to get her engine running and gauges working and will fan out from there to the less critical stuff like lights, etc.

Too much fun!!!
 
Back to top
View user's profile
modirt
Regular


Joined: 17 Nov 2018
Posts: 235


Report to Moderator

PostPosted: Wed Jul 03, 2019 4:54 am    Post subject: Re: Replacement wiring harness Reply to specific post Reply with quote

Hmmm.......did some more homework and seeing the comment on the other wiring harness thread about the need for all electric power loads to flow through the amp meter before anything else.........the light finally came on.

My wires were reversed. Wires coming from the battery should flow through the amp meter before it goes to the starter switch. And the second wire from the alternator connecting at the same place just provides an additional pathway for power to the switch, which also makes sense, since this vehicle has an abundance of headlights and flood lights up front for night time operations. All that connecting up before it goes to the starter switch makes sense.

There is even a 3rd wire running directly from the battery to a harness that feeds some of the light switches, plus there is a tray for a 2nd battery.......curious when one 12 volt battery is more than enough to start and run the engine. All those lights may have created a high electric load. Explains a lot.
 
Back to top
View user's profile
:   
Post new topic    Yesterday's Tractors Forum Index -> Restoration and Repair Tips All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). We have the parts you need to repair your tractor - the right parts. Our fast shipping, low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

YT Home  |  Forums

Modern View Forum 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