Electrical Issue With International Harvester Frame Is Hot

I recently purchased a 1957 International Harvester Model 350 Utility. I have not been able to start for a couple of weeks now. Today we installed new solenoid from NAPA. While it was out of the tractor I decided to replace all wires and terminals in this circuit, just in case. I matched the wires that were on the tractor. 10 gauge from the solenoid to the toggle and 14 gauge the rest of the way. While we were at it, we decided to replace the toggle switch as well. The only old equipment is the push button starter. All connections clean and new and tight. No start. Put the 12 volt test light on the negative side of the battery terminal and began the testing once again. The tractor is a negative ground. Power at the positive side of the battery, power at the large bolt on the solenoid, power at the toggle switch, power at the push button starter. With the toggle on, power at the outgoing toggle connection, power at the push button, and power at the small bolt on the solenoid when the push button is pushed. All good, right? Unfortunately also power at the frame. Put the multi-meter on all of the above connections for power, which we had 12.55 volts, same as the battery. When testing the frame, also at the 12.55 volts? Where is the cross over from negative to positive? Removed the coil wire from the toggle switch to see if that might be the issue, tested the same as connected, so I assume that is not the problem? I did also jump the starter, which turned over. The frame is only hot when the push button is pushed, toggle on or off. If the push button is not pushed, no power to frame? Push the push button starter button and it lights the frame up? I also am questioning the key starter circuit? This has a heavy wire coming from the negative side of the battery bolted to this key switch area. Another bolt hitches a heavy wire that connects directly to the frame. That is all on the negative circuit. Sorry about all the details, but I am confused for sure. I wonder how there is a cross between the negative and positive side of the battery? Could the starter be bad and somehow shorting to the frame? Thanks for your thoughts.

The negative side of the battery should have a
heavy battery cable going from a quality
battery terminal to ground (preferably on a
starter mount bolt. This battery cable should
be at least 2 gauge wire. It supplies the
complete ground system for the tractor. No
"extra" wires should be between those
connections. (I think this is the main issue)
From the positive terminal of the battery there
should be one battery terminal only hooked to
the same size 2 gauge cable, no other
connections.
The other end of this cable goes to the starter
relay (solenoid it is often called). That
relay should have 4 terminals 2 big and 2
small. The small terminals are labeled S and
I. (If only 3 all is well) The S terminal goes
to the push button for starting, 12 ga is good.
The big terminal close to the S terminal goes
to the above mentioned + battery cable. That
big terminal also has a #10 wire hooked to it
going to the amp meter (only there).
The Other big terminal on the relay goes to a
metal connector attached to the starter input
terminal.
The "I" terminal on the relay goes to the
ignition coil + side. It is to bypass the
ignition resistor giving the coil full voltage.
If this is not there we will worry about it
later, it is not needed if the coil is a full
12v coil with no resistor required. Get this
wiring correct and lets go from there. Jim

Starter is shorted internally.

If I'm reading the original post correctly, with the meter negative on the battery, and the frame showing 12.55, there is a bad connection between the battery ground and the tractor frame/motor/starter. I'd start by replacing the negative cable, and making sure it goes to a clean solid connection on a casting. You can test by using a jumper cable from battery Neg to a starter mounting bolt (if clean).

Let us know if that works

Great idea, thank you all. I just found out that
this key switch is called a battery disconnect
switch. There seems to be an issue with it. I
will use jumper cables and try. I will remove the
ground cable from the negative battery terminal
and hitch the jumper cable to negative and the
other end to the starter bolt. Let us hope. I
will let you know as soon as I try. Thanks again.

Did jump the negative terminal to the starter bolt and eliminate the battery disconnect switch. The frame was not hot and power was where it should have been. Reconnected the negative cable to the battery terminal that goes to the battery disconnect switch and the frame became hot. Put everything back together and gave her a go. Unfortunately I believe my battery is toast The starter turned over and wanted to go, but just did not have enough juice. Guess I need a new battery? Take a look at the attached pictures. One is of the back of my battery disconnect. The other shows the entire set up that has been giving me fits for several weeks. You can see the battery, battery disconnect switch, dashboard with push button, the toggle is just under to the right if you look closely. The new solenoid is to the left with new red and white wires. Hope this helps clarify what I am looking at.

Hi Commoner,

First thing I notice is that the terminal on the right of your battery disconnect shows it's gotten hot, which indicates that it has a bad connection. I'd shorten that cable and replace that loop, or replace the cable. It doesn't take much resistance at 150 or so amps during start to drop the battery voltage to where it may seem weak. If you have a volt meter, check the battery voltage - it should be a minimum of 12.6. Freshly charged (but with the charger off), it can be as much as 13.2 or so. Don't even bother checking it with the charger on, as it won't tell you anything relevant to the battery condition. With a fully charged battery, have someone crank the motor while you are measuring the voltage between the battery neg post and the frame - it shouldn't show more than about .5v (1/2 volt) If it does, there are definitely problems in the neg side of your circuit, which may include a problem with the battery disconnect switch.

Second thing, NORMALLY, a battery disconnect goes in the non-grounded side of the circuit, in your case, the + side. Not that it HAS to be done that way, it's just quite odd to do otherwise.

Other than that, the fact that it cranks says you're getting close to having it fixed.

Looks wrong to my eyes. You have a battery cable straight to the starter, and the starter switch from the other side of the battery to ground? Am I seeing that right or is that your disconnect switch??

Actually is is difficult to see in the picture. The cable coming form the positive on the battery terminal connects to the solenoid, large bolt on top. The red wire goes to the toggle. The white wire comes from the push button. The negative is not hitched in the picture to the battery terminal. The way it is usually wired is the negative feed from the battery goes to the battery disconnect switch. The other side of the disconnect goes to the ground on the frame near the starter. Thanks for your thoughts. Looks like a new battery is next.

You started with 12+ volts measured all over the place. You said the engine turned over when you jumped somehow. I don't see how you get from that to a bad battery.

Although I didn't follow all your places you measured voltage, the ones I did all suggest a bad ground. Were those readings taken with the ground disconnected? If so they look normal. If not you need to fix your ground connections.

You have clamp-on battery connections on your cables. Do they have clean connections to the cables? Connect the battery ground cable directly to the tractor frame, bypassing your disconnect switch. See if it starts that way. The more connections the heavy cables go through, the more potential trouble.

I did have 12+ volts all over and these were
taken with the ground connected, so it does
look like the ground is the issue. I may be
using the incorrect term, the starter turned
over, not actually the engine. There does not
seem to be enough power for that. This is an
older battery, it is very cold here, and the
tractor does not have a generator to recharge
the battery once started. Sorry to leave these
details out. It seems like the battery
disconnect switch is my problem, at least at
this point. I agree with the direct ground
from battery to frame and bypass the battery
disconnect to see if I can get her started.
Will get the battery tested for a load at a
local shop and see where we are, but it appears
the battery may be beyond its useful purpose?
Also will connect the negative battery terminal
directly to the frame with good and clean
connections. Thanks for your thoughts.