1962 Farmall 504 Row Crop wiring issue

Hello, I just purchased this tractor and I would appreciate any assistance on the 3 issues I have on this tractor. Probably all related.



Tractor runs on ( diesels ), when key is turned off. ( PROBLEM # 1 )

* I believe it to be electrical. I have adjusted timing both advanced and retarded with no change to the problem. So set properly

* new factory dash harness installed. These function as they should ( lights, dash lights, fuel gauge, temp gauge, oil light )

* Has a one wire alternator ( only wire on it was connected from ALTERNATOR BATT to BATTERY wire ) GEN light bulb removed

* I assumed this was the issue, so I connected alternator output #2 ( side plug ) to alternator BATT output with the wire to BATT

* I then ran the alternator output #1 ( side plug ) to one side of GEN light, other side connected to IGNITION on Fuel/Temp gauge

* diode was installed on this output #1 wire

* GEN light now works properly, but will not shut of with KEY switch ( PROBLEM # 2 )

* when output wire #1 totally disconnect, GEN light is obviously dead, but no effect on problem ( run on / dieseling )

* When engine running, system is charging at 14.4 vdc

* All other wiring is I believe factory

* When the key is turned off, starting button voltage drops to 2.4 - 3.5 vdc ( best my Fluke meter can read ) engine knocks / sputters

* I feel like I have not isolated the feedback voltage



NOTE - If engine is cold ( started cold and ran for just a few minutes, before water temp comes up ) it shuts right off ???



PROBLEM # 3 - when lights are turned on, they all work, pulling around 5.5 - 6.8 amps ( read with Fluke clamp on meter ), but the resistor on
the light switch gets very hot. Smoked some at first as it burnt off factory coating. ( purchased as a direct IH part from Steiner ). IS THIS
NORMAL ?



* Additionally, the input BATTERY amperage to the light switch reads NEGATIVE amps??? LIGHT wires read POSITIVE amps on same
Clamp on Fluke meter.



Any help would be greatly appreciated



Thank you
 

If you disconnect ALL wires from the alternator does it still ''run on''?

If so, something must be connected wrong in the ignition circuit, perhaps involving the ''starting bypass''.

Below is a link to the factory wiring diagram for reference.

https://cdn.compknowhow.com/carterandgruenewald/wiring_diagrams/IH 404-2404-504-2504.pdf

I realize you have ''updated'' the alternator, but if it ''runs on'' with the alternator disconnected there's something wrong in the rest of the wiring.
 
Dieseling is not electrical, it is either an Idle set too high (should be set to about 450 or as low as possible running OK), or carbon hot spots making combustion happen.
The not shutting off could be 2 things it needs a diode in the wire from #1 terminal on alt to the ignition, but it must block voltage from alternator and allow voltage to go to the alternator (diode band to alt side). The Delco while excited puts charging voltage on that wire which then causes the light to have 12v on both leads shutting off its illumination. The alt light could do this (stand alone) without the diode if it is a small wattage bulb. If it has been converted to electronic ignition, the trigger voltage could be as low as you found. Reverse the ammeter wiring and the meter will read charge when charging, if the delco is connected through it. or discharge if the delco is connected directly to the battery. Jim
 
Very simple test, with it warmed up, ignition off and engine still running, pull the coil wire and see if it stops the running.

If it continues to run, then the problem is not electrical.

Ignition timing has nothing to do with run-on other than changing the idle speed. Setting the idle as low as practical and being ready to kill it with the clutch is about the only option.

Looking at the wiring diagram, it appears the resistor on the light switch is for dimming the instrument lights and should only be wired to the instrument lights. If it is getting excessively hot there may be something wired to it that should not be, but it is normal for a resistor under load to get hot.

As long as the battery is charging, is not discharging when shut off, it appears to look like everything is normal.
 
I am no IH expert, but I worked on a Minneapolis-Moline M5 once that would diesel and found it had LP gas heads and oversize cylinders bored into diesel blocks. I don't know what the compression was, but it was too much compression for pump gas.
It would diesel. You had to pull the throttle all the way closed, leave in gear and ease out the clutch when you turned the switch off.

Is there any chance your 504 is like this?
 
I will try that next. I did disconnect all the wires from the alternator, so only battery power, the engine still ran on. If it dies with coil wire off, and you look at the wiring explanation I posted, what would be you thoughts after that. Could an aftermarket switch or starter button have any bypass voltage?

Also, that makes sense on the lights, I will have to verify the wiring of the switch and if the headlights are connected to the instrument lights.

Thank you for the advise.
 
I removed all wires from the alternator, started engine, let it warm up, and it still ran on. Going to pull coil wire as suggested by another
member next. If that kills the engine, then I am wondering about voltage pass by on switches, starter button, etc. ???



Thank you for your advise



Dave
 
I verified the diode is installed in with the correct bias, but are you saying to run this wire to the key switch instead of the battery wire?

Sorry, didnt follow you there. As I posted this #1 wire is only connected to the GEN light now, which feeds back to the ignition connection on the instrument cluster.

Thank you for your advise
 
It may eventually stop on its own, but I do not let it continue. I have to let clutch out with it in gear and brake on to kill it.



Thank you
 

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