John Deere 730 Diesel Pony 6v to 12 v conversion wiring diagram.

[Chuck430C]

Anyone have a wiring diagram of how to convert the 6 volt pony system on a JD 730 Diesel CE to 12 volts? Coils will still be 6 volts. Would this be accomplished by adding another resistor? Any other resistors or mods needed? All lights and motors will be 12 volts.
Seems like several on here have stated in the past that a few people had made a diagram.
Thanks in advance for any assistance!

 

[Scott 730]

Anyone have a wiring diagram of how to convert the 6 volt pony system on a JD 730 Diesel CE to 12 volts? Coils will still be 6 volts. Would this be accomplished by adding another resistor? Any other resistors or mods needed? All lights and motors will be 12 volts.
Seems like several on here have stated in the past that a few people had made a diagram.
Thanks in advance for any assistance!

What is the end goal here???

 

[Chuck430C]

Scott,

Thanks for your reply!
I want to run everything but the coils on 12 volts. The only coils I have found are still 6 volts. My starter, generator, and lights are 12 volts.
Factory wiring provides 6 volts while starting the pony and cuts to about 4.5 volts when starter button is released due to the resistor in the circuit.
I recall from years back that some have converted to 12 volts in a way that only provided factory voltage to the coils.
Brighter lights and longer lasting battery along with not risking burning up expensive coils are the goals.

Thanks!

 

[Janicholson]

Anyone have a wiring diagram of how to convert the 6 volt pony system on a JD 730 Diesel CE to 12 volts? Coils will still be 6 volts. Would this be accomplished by adding another resistor? Any other resistors or mods needed? All lights and motors will be 12 volts.
Seems like several on here have stated in the past that a few people had made a diagram.
Thanks in advance for any assistance!

The pony starter motor is probably OK with 12v. the coil needs a ballast resistor to stay cool. Resistors in a starter motor circuit would be tremendous and about .1 ohms. Then they would get hot and draw effective power from the starter as though it had bad cables/ Jim

 

[wore out]

Scott,

Thanks for your reply!
I want to run everything but the coils on 12 volts. The only coils I have found are still 6 volts. My starter, generator, and lights are 12 volts.
Factory wiring provides 6 volts while starting the pony and cuts to about 4.5 volts when starter button is released due to the resistor in the circuit.
I recall from years back that some have converted to 12 volts in a way that only provided factory voltage to the coils.
Brighter lights and longer lasting battery along with not risking burning up expensive coils are the goals.

Thanks!

You will need to add a resistor ahead of the WICO "ignition box" to reduce the higher battery voltage to where it is now.

You will have to determine the value by experimentation, as the available primary ignition resistor values vary by quite a bit and this is a non-conventional application for one, which won't be documented in a parts catalog.

Are you familiar with adding an oil pressure switch so the coils won't be overheated if the switch is left "ON" with the engine not running?

A little searching the archives here or GOOGLE should come up with that.

 

[Chuck430C]

You will need to add a resistor ahead of the WICO "ignition box" to reduce the higher battery voltage to where it is now.

You will have to determine the value by experimentation, as the available primary ignition resistor values vary by quite a bit and this is a non-conventional application for one, which won't be documented in a parts catalog.

Are you familiar with adding an oil pressure switch so the coils won't be overheated if the switch is left "ON" with the engine not running?

A little searching the archives here or GOOGLE should come up with that.

Thanks for your reply!

I recall reading about a 3-4 lb oil pressure switch that was N/O. Is that the one? Could I "T" the oil line in to the one operates the gas bladder valve?
Do you have a part number and/or source for that oil pressure switch? Thanks!

 

[Chuck430C]

The pony starter motor is probably OK with 12v. the coil needs a ballast resistor to stay cool. Resistors in a starter motor circuit would be tremendous and about .1 ohms. Then they would get hot and draw effective power from the starter as though it had bad cables/ Jim

My starter, generator, and lights are all 12 volt so no voltage reduction needed on them.
Just need to make sure I pour the right voltage to those $$ coils.

 

[rustred]

The pony starter motor is probably OK with 12v. the coil needs a ballast resistor to stay cool. Resistors in a starter motor circuit would be tremendous and about .1 ohms. Then they would get hot and draw effective power from the starter as though it had bad cables/ Jim

do you know how fast that v4 engine spins over on 6 volts? like probably twice as fast as an ih. with 6 volts,.. and about as fast as a 12 volts on the 6 volt starters. so i would hate to see it spin. on 12 volts. you would be able to start the diesel engine just by cranking it with it engaged. and those 2 coils and points burn out pretty quickly if the switch is left on. so to me the simplest deal is to keep the 6 volts , a 6 volt battery is pretty cheap compared to experimenting with 12 volts. so i am curious on the end goal also.

 

[Chuck430C]

do you know how fast that v4 engine spins over on 6 volts? like probably twice as fast as an ih. with 6 volts,.. and about as fast as a 12 volts on the 6 volt starters. so i would hate to see it spin. on 12 volts. you would be able to start the diesel engine just by cranking it with it engaged. and those 2 coils and points burn out pretty quickly if the switch is left on. so to me the simplest deal is to keep the 6 volts , a 6 volt battery is pretty cheap compared to experimenting with 12 volts. so i am curious on the end goal also.

My starter and generator are original casings but rebuilt for 12 volts so no issues with RPM of starter.
The goal is to run the coils on 6 volts and everything else on 12 volts.
It has been done, I have seen it on here in the past.

 

[PJH]

Anyone have a wiring diagram of how to convert the 6 volt pony system on a JD 730 Diesel CE to 12 volts? Coils will still be 6 volts. Would this be accomplished by adding another resistor? Any other resistors or mods needed? All lights and motors will be 12 volts.
Seems like several on here have stated in the past that a few people had made a diagram.
Thanks in advance for any assistance!

I don't have a wiring diagram. It sounds like you want to use a 12-volt battery and get away from the 6-volt battery. Could you live with two 6-volt batteries? I don't know if two 6-volt batteries will fit in your battery box. My brother has a nice little 47 Plymouth coupe that was 6 volts in a previous life. He converted it to 12 volts using a common Delco alternator, but he used two 6-volt batteries in series. He also installed an overdrive transmission that demands 6 volts for solenoid operation, and then there's the old 6-volt radio. He feeds the overdrive solenoid and the radio off of one of the 6-volt batteries. The 12-volt batteries in the old days were more convenient. They had external "straps" connecting the individual battery cells and you could run a fat sheet metal screw into the appropriate strap for various voltages. Having said all of that - it sounds like you might not be making an improvement of the original system. Maybe you are using implements like a baler or planter that requires 12 volts?

 

[Chuck430C]

You will need to add a resistor ahead of the WICO "ignition box" to reduce the higher battery voltage to where it is now.

You will have to determine the value by experimentation, as the available primary ignition resistor values vary by quite a bit and this is a non-conventional application for one, which won't be documented in a parts catalog.

Are you familiar with adding an oil pressure switch so the coils won't be overheated if the switch is left "ON" with the engine not running?

A little searching the archives here or GOOGLE should come up with that.

Here is the link to the Green Magazine article by Frank B adding the safety switch to coils.

Save Those Pony Coils! - Green Magazine

A few weeks ago, I was trying to diagnose a problem I was having with my 70 diesel. The pony motor (or starting engine to you purists!) clutch seemed to be in adjustment one day, and out the next. One evening during one of my sessions, the pony engine stalled or ran out of gas […]

greenmagazine.com