(800) 853-2651
SHOP NOW

Ground Conversion Question

F

FordsonDexta

New User
Hi all, I recently acquired a fordson dexta and am wondering how I can tell if it has been converted from positive ground to negative ground as it has no battery in it. It has delco remy alternator which I would think is 12 volts. If anyone one could please give me some tips about how to identify a negative ground conversion so that I don't hook up my battery the wrong way that would be greatly appreciated.
Thanks Again!
 
Unless modified, virtually all Delco alternators (both 10DN external regulator and 10SI internal regulator) are negative ground. However there are a couple ways you can determine ground polarity:

1 - Look at the specs stamped into the alternator case by the tensioning ear. The stamping will indicate factory voltage, ground polarity and rated output like this: 12V NEG 37A (= 12 volt, negative ground, 37 amps output).

2 - If your Dexta has an ammeter, temporarity disconnect ALL the wiring at the alternator. Now connect a battery negative with post to ground and turn on the lights. The ammeter will indicate discharge (hand moves to the left) if the tractor is wired negative ground.
 
Examine the alternator closely. There should be stamped on it the voltage output, how many amps it charges and whether it is + or - ground.
 
Thank you very much for your post, it was very helpful. Unfortunately the ammeter is missing, so replacing that will be a future project. A second question is- if my alternator turns out to be negative ground, then is it safe to say the battery get hooked up negative ground? Thanks again.
 
An alternator is negative ground. Look at the battery cables. The negative post is always smaller than the positive.They will tell you how it was last hooked up.
 
Yes, it will need to be connected negative ground.

When connecting the cables, everything turned off, when you connect the last cable, there should be no spark. If backward, it will pop and spark violently!

One other thing, the ignition coil. For negative ground, the primary connections need to be connected + to the ignition switch, - to the distributor. Those should have been changed when it was converted, but worth checking to be sure.
 
(quoted from post at 21:47:08 10/04/18) A second question is- if my alternator turns out to be negative ground, then is it safe to say the battery get hooked up negative ground? Thanks again.
Click to expand...

If the alternator is negative ground then the battery MUST get connected negative post to ground. (Connecting the battery positive ground to a negative ground alternator will fry the alternator instantly!)

Another way to determine alternator ground polarity: Make a small test light from an automotive side marker light or other small 12 volt bulb and a piece of wire.

Connect the tractor's ground cable to the battery neg post but do not connect battery the "hot" cable. Now take your test light and connect it between the hot cable and the battery positive post while observing the bulb.

If the bulb remains dark, the alternator is negative ground. However if the bulb lights, it says the alternator is positive ground.
 
99.9% of alternators here in the U.S. will be - ground. A Delco is going to be - ground unless modified which would not be very likely. One thing for sure is if you hook it up wrong it will start smoking the minute you hook it up. Don't ask how I learned that one
 
Steve, there should be no coil as 99.99% of Dexta were diesel, Just a smaller version of the Fordson Major or super major.
 
You must log in or register to reply here.

Similar threads

R
Alternator Confusion, Positive Ground
2
Replies
29
Views
1K
used red MN
U
M
4020 24v starting system wiring question
2
Replies
20
Views
560
Tx Jim
Tx Jim
R
How do I polarize a delco-remy 12v postive ground genera
Replies
6
Views
346
John T
J
C
Magneto kill switch with negative ground
Replies
13
Views
488
rustred
rustred
R
12v ground connection gets warm
Replies
4
Views
169
old
O
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