350 Ammeter Problems

jmcbmc

Member
My temp and ammeter gauges weren't working on a newly acquired 1958 350 utility tractor that was operating perfectly. I replaced the temp gauge/sending unit with no problem, but there were no wires running to the ammeter. It was obvious that the tractor had been converted to 12 volts at some point in time. I removed the controls panel and found that the start button had a wire from the solenoid on one terminal as expected, but had three wires on the other terminal. One wire was from the ignition switch, another wire was from the solenoid battery post, and the final wire was from the alternator BAT post. I tried wiring in the ammeter according to diagrams I found on the internet with no success! It looks like the problem is with the ignition switch which looks to be the original switch. Does anyone have a wiring diagram based on the original ignition switch?
 
The diagram I have attached is how your wiring should
be connecting. However, to be correct the wire for the
solenoid push button connecting to left side of the
ammeter SHOULD connect to the right side of the
ignition switch to keep the starter from engaging if the
ignition is not on. If you have a one wire alternator
disregard the connections to the two alternator side
terminals labeled 1 and 2.
12 volt alternator wiring diagram


This post was edited by used red MN on 11/12/2023 at 08:21 pm.
 
Usually when these old tractors are converted to 12 volts
they go with a voltmeter or the red charging light. Key on
light is on. Once charging the light goes out.
 
Thanks for the quick reply Used Red! You've confirmed the problem is in my ignition switch wires because the start button turns the engine over when the ignition switch is Off. I'll check it out tomorrow.
 
Rustred, this one has the ignition on light, and a standard ammeter. Is the ammeter problematic?

Thanks for replying!
 
He likes to wire them that way, supposedly a one wire conversion alternator has this in the instructions. I should have clarified that the wiring from the alternator to the ammeter and the ammeter to the starter solenoid should all be 10 ga. The voltmeter allows him to just run the wire off the alternator to the starter solenoid and avoid the higher amp wiring running up to the dash gauge and then down to solenoid. Wiring per the diagram with the heavier wire will give you no issues. If you have a 3 wire alternator with the dash warning light that will have to remain in place, that is part of the circuit that energizes the ..excite.. circuit in the alternator for it to start charging. The light also serves the purpose of not allowing enough amperage to back feed from the alternator to keep the coil firing when the ignition power is switched off so the engine shuts off. That is why you see it light up momentarily when you turn the key off.
 
(quoted from post at 06:03:50 11/13/23) Too avoid confusion 1958 IH 350 was 12 volt positive generator from the factory.
And now it has a Delco 10SI alternator, so it wasn't converted to 12 volts as I first stated, the generator was just replaced with an alternator. I must have to make sure the start button, light switch, ammeter, and ignition key are all externally grounded as if they were reinstalled in the instrument panel because right now with the new circuit, the start button doesn't work and the ignition on light is always on!
 
My alternator is 3-wire and I'm using 10ga wire as you suggest, but nothing's working!

I'll be gone for a few hours, so I'll get back to you guys later.

Thanks for the help!
 
Not sure what you have going on there, you have to wire it per the diagram. I am guessing you have connected wires to the side of the ignition switch that is always powered that should be on the side of the switch that turns on and off with the ignition. You should have one wire connecting to the ignition switch from the ammeter that always has power. Then on the opposite terminal of the switch you should have 1. a wire going to the ignition to power the coil, 2. A wire powering the start button, 3 a wire going to the charge light. The charge light socket should have a second wire that connects to the wire running to the number 1 side terminal of the alternator, in others words that charge lamp connects in a series. Did this ..ignition on.. light go out once the engine started and the alternator was charging? Sometimes the terminal 1 of these 3 wire alternators are wired using an ..Accessory.. terminal of a key switch. Is this what you had? If so the added lamp had no purpose and must have just always stayed lit. It would also be wise to make sure the coil terminated showing negative or minus is running to the distributor.

Edit: Sorry, I have a couple different diagrams I post depending on the type of start system you have. This is the one that shows a start solenoid. I forget this one shows a diode in the wiring to terminal 1 on the alternator. The dash charge lamp goes in there connected in a series replacing the diode.

This post was edited by used red MN on 11/13/2023 at 08:55 am.
 
(quoted from post at 09:39:23 11/13/23) Not sure what you have going on there, you have to wire it per the diagram. I am guessing you have connected wires to the side of the ignition switch that is always powered that should be on the side of the switch that turns on and off with the ignition. You should have one wire connecting to the ignition switch from the ammeter that always has power. Then on the opposite terminal of the switch you should have 1. a wire going to the ignition to power the coil, 2. A wire powering the start button, 3 a wire going to the charge light. The charge light socket should have a second wire that connects to the wire running to the number 1 side terminal of the alternator, in others words that charge lamp connects in a series. Did this ..ignition on.. light go out once the engine started and the alternator was charging? Sometimes the terminal 1 of these 3 wire alternators are wired using an ..Accessory.. terminal of a key switch. Is this what you had? If so the added lamp had no purpose and must have just always stayed lit. It would also be wise to make sure the coil terminated showing negative or minus is running to the distributor.

Edit: Sorry, I have a couple different diagrams I post depending on the type of start system you have. This is the one that shows a start solenoid. I forget this one shows a diode in the wiring to terminal 1 on the alternator. The dash charge lamp goes in there connected in a series replacing the diode.

This post was edited by used red MN on 11/13/2023 at 08:55 am.
k, I don't have a charge light, so there must be a diode somewhere because I have power to the coil. When the ammeter was bypassed the ignition light went out when the engine started. I don't see a wire on your diagram from the ignition switch that powers the start button, i.e. your #2?

You've given me enough info, so I can check all wires to make sure they're per your diagram. I suspect the problem is with the ignition wires or the start button wires.
 
what you have is a Billy Bob make over and god only knows . what or how was done. I know how i do a change over and i am OCD over it . , i like the three wire way and i do things a bit different , i build a new harness from dash out and i run and 8 ga. from hot post on the alt down to the solenoid i run a resistor for the stock coil wit by pass to feed a hot 12 volts from the S terminal on the starter to coil . If i am going to run a amp meter then we change that to one that will do 60 or better amps and run the hot from the alt to the amp gauge then to the hot post on the starter . If that 350 has the stock ing switch then it is just and OF on and to feed the dash i pull a 10 ga. off the hot on the starter up to a terminal block then feed ing and lights off it with a power wire to the push button off the ing switch . Lights are fed off the main terminal block/ Buss bar to a 20 25 amp self resetting breaker doing away with the fuse . i also stick with correct wire colors , that is just me as i hate one or two color rewires . Blue hot off alt to starter or Amp gauge if use red from amp gauge to starter black from key switch to coil Yellow and green to the alt.
 
Sorry, did not think I had to repeat what said in my first
reply where I linked the diagram there; I said it did not
have the preferred connection to power the start
button and told you where to connect it. Even though it
is not original as a ..charge light.. it was placed there
to do the same job as the diode as I explain in a later
reply. If need be print out the diagram and find a wire
or circuit between two points. Go to your tractor and
make sure you have a wire making those connections,
then put an X on it. Once you have an X on all the wires
on the diagram it should work correctly.
 
(quoted from post at 13:09:40 11/13/23) Sorry, did not think I had to repeat what said in my first
reply where I linked the diagram there; I said it did not
have the preferred connection to power the start
button and told you where to connect it. Even though it
is not original as a ..charge light.. it was placed there
to do the same job as the diode as I explain in a later
reply. If need be print out the diagram and find a wire
or circuit between two points. Go to your tractor and
make sure you have a wire making those connections,
then put an X on it. Once you have an X on all the wires
on the diagram it should work correctly.
orry about missing your start button power input wire instruction in your first reply! Connecting the wire you identified is the only way I've been able to get the start button to work, so now things are starting to make sense. I'm in the process of making your wire checklist.
 
(quoted from post at 13:54:18 11/13/23)
(quoted from post at 13:09:40 11/13/23) Sorry, did not think I had to repeat what said in my first
reply where I linked the diagram there; I said it did not
have the preferred connection to power the start
button and told you where to connect it. Even though it
is not original as a ..charge light.. it was placed there
to do the same job as the diode as I explain in a later
reply. If need be print out the diagram and find a wire
or circuit between two points. Go to your tractor and
make sure you have a wire making those connections,
then put an X on it. Once you have an X on all the wires
on the diagram it should work correctly.
orry about missing your start button power input wire instruction in your first reply! Connecting the wire you identified is the only way I've been able to get the start button to work, so now things are starting to make sense. I'm in the process of making your wire checklist.
Used Red, you did it! Everything works as it should, but it won't shut off when you turn the key to off. So, all I have to do is put a diode in the #1 wire from the alternator is that correct??
 
You did it! Everything worked as it should, but the tractor wouldn't shut off when I turned the key off. Now all I have to do is put a diode in the alternator #1 wire, is that correct??
 
Here's one for a 450. Should be near the same
cvphoto166644.jpg
 
(quoted from post at 16:58:24 11/13/23) Here's one for a 450. Should be near the same
<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto166644.jpg>
hanks, I'll take a look at it!
 
Here is a diagram for an H or M. Look at the circuit
feeding the ..1.. terminal. It has the light in a series just
as I suggested yours should be. You do not need a
diode if the light bulb is the proper resistance which it
must be if it shut off before and charged the battery.
Let me state it a little differently. What you are
experiencing now is the charge voltage of the
alternator continuing to power the coil. If the light is in
the terminal 1 or excite circuit the filament of the bulb
cannot carry enough amperage to operate the coil. So
when you shut of the ignition power and the alternator
tries to power the coil the light bulb lights up and the
engine dies because as I just said the connection back
to the coil through the filament cannot support spark
because the voltage to the coil drops to low. Make
sense? Sorry if it does not. To me it as just as clear and
sure as when I crawl on a creeper to get under a car I
will certainly bang my melon.
 

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.

Back
Top