Ford 851 Electrical Conversion Schematic

[Ford851]

Hello again,

Can anyone explain to me what a Ford 851 electrical layout is suppose to be after it has been converted over for 6 volt to 12 volt? I took my tractor apart to work on the sheet metal. This took about 4 months. Now I'm fitting the metal parts back on the tractor and realized that the wires are not where i left them. My pet cats have had a field day playing with the dangling wires. I know i should have labeled them, but it seamed so simple at the time i took it all apart. Its like I think I know but then again I could make a mistake and burn up the wiring.

Let me try to explain what I think I have:

Starter circuit----From the 3 pole solenoid.
1. Battery 12 +(Red cable) to the large terminal on the solenoid
2. Opposite side of solenoid (large terminal) to starter terminal.
3. Center post on solenoid (white wire) goes to starter button in front of driver's seat.

The charging circuit---
1. From the alternator a 10 or 12 gage wire runs to one side of the ammeter.
2. From the other side of the ammeter a 10 or 12 gauge wire runs to the plus side of the solenoid. Where the heavy red cable is attached that runs to the plus side of the 12 volt battery.
3. A splice has been put in the wire mentioned in number 2 which runs to the ignition switch post. Supplies 12 volts
4. The other side of the ignition switch then runs to a large white resistor. (about 1.5 ohms) Drops volts to 6 volts
5. The other post of the this resistor then goes by a white wire to the coil primary. Open and closed by points
6. Secondary of coil delivers high voltage to distributer center rotor and then out to plugs.

There was also a small two post terminal block bolted to the steering column and I can't remember what its function is.

The schematics i've seen so far in the manuals leave a lot to be desired when it comes to clarity. I'm curious about the ammeter circuitry. And also there is an orange wire in the harness which I have no clue as to what it does.

Any help at this point is greatly appreciated as I would like to get this tractor back in the field.

Thanks in advance,
Ford851

 

[Dollar Bill]

Are you using an alternator or generator for the conversion? If alternator - Is it a one or three wire?

Here's the schematic for a 12 volt conversion using a one-wire GM alternator. HTH

 

[strum456]

The block takes the power from the ammeter and powers everything. Take a 10 or 12 wire from the ammeter to the junction block and then run the lights ignition and anything else off of that.

 

[Ford851]

Thanks for the quick reply from Dollar Bill and strum456. But unfortunately I can't read the schematic from Dollar Bill. On screen or downloading and printing. Its too blurry. However, thanks for trying. And to answer your question. Its a one terminal alternator. Could you email the schematic if I give you an address?

Thanks to strum456 for the info on the terminal block. I'll incorporate this. Does the terminal block go before the ammeter or

 

[Dollar Bill]

Ford851, check your email.

 

[strum456]

Thanks for the quick reply from Dollar Bill and strum456. But unfortunately I can't read the schematic from Dollar Bill. On screen or downloading and printing. Its too blurry. However, thanks for trying. And to answer your question. Its a one terminal alternator. Could you email the schematic if I give you an address?

Thanks to strum456 for the info on the terminal block. I'll incorporate this. Does the terminal block go before the ammeter or

Your junction block splits everything up after the ammeter which gets its power from the battery. So you run a heavy wire from the bat to the ammeter then annother to the junction then from the junction to your key switch light switch etc.. Your a 1 wire alt goes straight to bat. Dont forget a resistor unless you have a 12v coil. And if your ammeter works backwards just flip the wires. Hope this helps.

 

[Soundguy]

you are not wired correctly.

in short.. that should have a 4 post solenoid.. though a N style 3 poster will work.

also.. the ammeter goes between bat and alternator. all loads.. like key switch and lamps go on alternator side. NOTHING else goes on bat side.

them are the basics.

plus.. I'd ditch that power wasting resistor and old 6v coil and get a native 12v coil like a napa IC14sb 16$ coil.

if the alternator is 1 wire.. that's about it. if a 3 wire, then loop a wire from #2 spade to charge stud, then run a wire from #1 spade thru a 194 marker lamp to coil side of key switch. key on lamp on.. after starting and getting to 400 rpm or so lamp goes out and alt comes on.

ps.. amp gauge wasn't in an 01 either.. was a charge lamp.. should be fuel, oil and temp and proofmeter

soundguy

 

[Ford851]

Special Thanks to Soundguy. Will change to 4 post solenoid and coil. Where can I find the idiot light? What is the diode that I need? What size wire do I use? And where do I mount the diode? Also, can you tell me if a diesel fuel tank is identical to a gas fuel tank except for the return line hole? Can a diesel fuel tank be used to replace a gas fuel tank if it is cleaned by a radiator shop?

 

[Dollar Bill]

can you tell me if a diesel fuel tank is identical to a gas fuel tank except for the return line hole? Can a diesel fuel tank be used to replace a gas fuel tank if it is cleaned by a radiator shop?

Yes. Dimensions and bolt up are the same between 801 gas and diesel. If the diesel tank comes with a fuel sending unit, it will be 12 volts vs 6 volt for the gassers. Return line is easily plugged with a pipe fitting.

Dennis Carpenter has the Generator Warning Light: Dennis Carpenter

Soundguy will be along directly to answer your shocking questions.

 

[Soundguy]

if you are not familiar with diodes.. I'd skip them and just use a 194 marker lamp in the #1 spade wire to the key switch.

you CAN change to a 4 post ford or leave the 3 post if it is a ford tractor style and works with the thumb interlocked starter button.

difference inthe 4 post is that one small post goes to coil side of key and the ohter to the thumb switch.. that way you can only crank starter with key on. with 3 poster.. starter will crank with key off.

either works..

diesel tank on gas? I guess.. leak line is the difference mainly... probably gonna smoke good for a while...

I use 14awg wire for all my 12v wireing except charge line to ammeter and from ammeter.. for that I use 10 or 8.. if it's not available.. double up some 14 or 12.. will be fine.. nice thing about 12v is current is less for same wattage..

ps.. instead of using the 194 marker lamp.. just get a panel mount lamp from an auto store and use that to excite the alternator.. get something that uses about the same wattage as a 194 lamp. too low of wattage and the alt won't turn on correctly.

wire from coil side of key, to lamp, to #1 terminal on alt, if a 3 wire alt.