Case SC 12V Conversion

I mentioned this in another thread and it was suggested that I start a new thread. So, here we are.

I have a '45 Case SC that I recently purchase. It was previously converted to 12V, but not done neatly or correctly, according to my research. So, I have completely re-wired it.

I combined the original SC wiring diagram with one I found for a Farmall 12V conversion, here on this forum. Using these two diagrams, I drew up my own for the SC 12V conversion.

Note: I am not an electrician by any stretch of the imagination. I would appreciate any corrections that may need made to my diagram.

Here is my conversion diagram.
Case%20SC%2012V%20Conversion-L.jpg


Here is the original wiring diagram.
Case%20SC%20Original%20Wiring%20Diagram.jpg


Here is the Farmall 12V conversion. I do not know who originally posted this or I would give credit where credit is due.
Farmall%2012V%20Conversion.jpg
 
Other than to share my diagram, I'm also still having a lingering issue. Something is drawing off the battery when not running. However, I'm not sure I had the "Ign Switch" in the off position. Is there anything else that could put a draw on this system?
 
I have had the diodes in the alternator short out and drain the battery. Try unhooking battery wire on the alternator and see if it still drains.

Eli
 
To avoid having to turn off the power to the alt, you can pick up a very inexpensive diode kit for that or, like I do, an oil
pressure switch that closes the circuit with pressure, NAPA has one that completes the circuit at 5# pressure, similar to a switch
that operates the early hour meters. Avoid the 1 wire alternators the street rodders use because of the rpm needed to energize the
field
 
(quoted from post at 17:18:37 07/18/16) I have had the diodes in the alternator short out and drain the battery. Try unhooking battery wire on the alternator and see if it still drains.

Eli
Unhook both the post and terminal 2 connections?
 
(quoted from post at 17:20:26 07/18/16) To avoid having to turn off the power to the alt, you can pick up a very inexpensive diode kit for that or, like I do, an oil
pressure switch that closes the circuit with pressure, NAPA has one that completes the circuit at 5# pressure, similar to a switch
that operates the early hour meters. Avoid the 1 wire alternators the street rodders use because of the rpm needed to energize the
field
Would leaving my "Ignition Switch" on cause the battery to drain?
 
If you have a mag yet the ignition switch is just a ground for the primary (low voltage) part of the magneto. One thing to think
about, I had this issue with both of my SC's when I went 12 volt. The starter now spins quickly enough to disable the impluse
coupling of the mag. This winds up and flips the mag as it's rotating at cranking speed, either with the hand crank or the
starter. The spark will be weak......sometimes leads to hard starting. I switched both to distributors and have had no issues
since. Also, on your diagram you're showing a 10 gauge wire to carry the current back to the battery, you don't need that. 12 ga
with 12v is adequate
 
You can't have the magneto and the alt hooked to the same kill switch.

When using a alt with a magneto. I like to use a two terminal oil pressure switch added to the back side of the oil pressure
gauge. Hook the alt to the oil pressure switch.
 
Take a look at my drawing. There are two switches. The one going to the magneto is labeled "kill switch". The one on the alternator is labeled "ign switch".

If this switch on the alternator is left on, would that drain the battery?

Also, where can I find the oil pressure switch? I like the automatic function that would provide.
 
(quoted from post at 06:37:35 07/19/16) Yes leaving the switch on will run the battery down.
Ok, thanks. Hopefully that's what I did. I've been leaving the battery disconnected until I got some answers. I will hook it back up and monitor it. If it still is going dead I'll disconnect the "battery" lead from the alternator.
 
Oil pressure switches are pretty common. You could ask for one like what was on the old Chev Vega. Th Vega was set up so if oil pressure dropped below 15PSI it would shut the engine off so as not to hurt the engine.
 
If he used the correct switch yes he could have both hooked up to one switch. A simple double pole switch would do the trick. One side would be set up to turn on the alternator while the other side would unground the mag
 
I would put an inline fuse between the starter switch
and amp gauge.
I feel most tractors are not properly fused. The feed
wire from the solenoid to the dash mounted fuse
holder on my 530 Case shorted out and caused the
wiring harness to catch fire. I now out an inline fuse
on all my tractors at the closest possible point to the
hot battery cable.
Also I have used several one wire delco alternaters, I
just Rev the tractor up once it has ran a few minutes
to make it start charging. It will continue to charge
regardless of RPM until the engine is shut off.
Nick
 
(quoted from post at 00:45:09 07/19/16) Other than to share my diagram, I'm also still having a lingering issue. Something is drawing off the battery when not running. However, I'm not sure I had the "Ign Switch" in the off position. Is there anything else that could put a draw on this system?

blsnelling When you get it figured out can you update your drawing It would help a lot of folks out there.

I saw you were asking about the seal for the axle I remove the 4 bolts on the cap and cut a felt seal This seal is to big for the end any. I installed it with the cut at the top of the axle hasn't leaked yet. I did it this way because I had nothing to remove the wheel weight and wheel rim. I did remove the tire just to get it out of the way. Call John at external_link 315-585-9826
Case S SC D DC O5824AB 05824AB Felt Wheel Seal

$9.95

38194.jpg
 
(quoted from post at 00:45:09 07/19/16) Other than to share my diagram, I'm also still having a lingering issue. Something is drawing off the battery when not running. However, I'm not sure I had the "Ign Switch" in the off position. Is there anything else that could put a draw on this system?

blsnelling When you get it figured out can you update your drawing It would help a lot of folks out there.

I saw you were asking about the seal for the axle I remove the 4 bolts on the cap and cut a felt seal This seal is to big for the end any. I installed it with the cut at the top of the axle hasn't leaked yet. I did it this way because I had nothing to remove the wheel weight and wheel rim. I did remove the tire just to get it out of the way. Call John at external_link 315-585-9826
Case S SC D DC O5824AB 05824AB Felt Wheel Seal

$9.95

38194.jpg
 
(quoted from post at 00:45:09 07/19/16) Other than to share my diagram, I'm also still having a lingering issue. Something is drawing off the battery when not running. However, I'm not sure I had the "Ign Switch" in the off position. Is there anything else that could put a draw on this system?

blsnelling When you get it figured out can you update your drawing It would help a lot of folks out there.

I saw you were asking about the seal for the axle I remove the 4 bolts on the cap and cut a felt seal This seal is to big for the end any. I installed it with the cut at the top of the axle hasn't leaked yet. I did it this way because I had nothing to remove the wheel weight and wheel rim. I did remove the tire just to get it out of the way. Call John at external_link 315-585-9826
Case S SC D DC O5824AB 05824AB Felt Wheel Seal

$9.95

38194.jpg
 
(quoted from post at 12:34:33 07/19/16) If he used the correct switch yes he could have both hooked up to one switch. A simple double pole switch would do the trick. One side would be set up to turn on the alternator while the other side would unground the mag
I like this idea a lot.
 
Your issue with the wheel leaking gear oil If you don't want to remove the wheel rim the tractor looks nice no reason to mess it up . Just remove the cap on the axle 4 bolts and install a felt seal behind the cap. I simply cut mine at the top no oil there and installed it because I was not going to remove the rear wheel weight and rim just to get the seal on in one piece. It has never leaked since. I removed just the wheel and left the rim and weight on there to give me more room.

When you get your electrical fixed can you please update your drawing a lot of folks can benefit from it. I personally would appreciate it.
Best of luck Byron
 

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