49 farmall c

Could someone tell me what type of electrical system a 1949 c would have had originally? I.e. ( 12v, 6v, positive ground, negative ground)? I redone the wires grandpa had on the tractor today to get it started for the first time in many years. He had it wired as follows, 12v battery with negative terminal grounded to the chassis, single wire running from distributor to the positive terminal on the back of the coil, and what stumped me was he had a single hot wire running from the negative terminal on the back of the coils to the hot post of the battery with an alligator clamp. Any help is appreciated.

6 volt negative ground

sorry, it should be 6 volt positive ground

Okay thank you for the input. How does a positive ground system work because that stumps me. You don’t actually ground the positive battery terminal to the chassis or do you?

you do..........dewy

Positive side of the battery should be grounded. Negative side of battery should run to the negative side of the coil.

First question all should ask is does it have the original 6 volt positive ground generator and regulator or cutoff or has it been replaced with a 12 volt negative ground alternator.

Okay and then run another wire from the negative battery terminal to the metal button mounted on the starter as well?

It does currently have an altinator on it although it isn’t hooked up in any way it’s just mounted on the tractor still. I want it to be as close to all original as it was when it was brand new.

Sounds like you are dealing with a partially completed 12 volt negative ground conversion. To be usable as 12 volt a true 12 volt coil would be required or a resistor installed to use with a 6 volt or 12 volt resistor required coil properly wired thru the switch, as well as finishing the alternator wiring and light bulb changing.

Whoa, let us not go off on any bad tangents here and unleash any of the precious smoke keepers. Look at the reply in the attached post with the photo-bucket label over it. That diagram shows you what the original wiring diagram is. A word of caution if you decide not to install a stock 6v system on your tractor you cannot connect alternator to a positive ground system. It will likely fry both your alternator and wiring. There are a few specialty built alternators that allow this but they are very expensive. If you are serious about ..restoring.. the tractor to original I would recommend getting a IH operator’s Manual and and IH Blue Ribbon repair manual. Also welcome to YT!
YT Post with wiring diagram

If it has a generator, it must have a positive ground. If it has an alternator, it must have a negative ground. Lots of people switch from a generator to an alternator, in that case you have to change the ground and follow the rewiring diagram the used red mm is referrring to. When electric componets are built, they are filled with smoke. If you hook something up wrong and let the smoke out, the part is useless and must be replaced. Make sure that you understand what you are trying to do before you get carried away and start sending smoke signals.

Hobbs, please don’t get confused by the post by Super99, the diagram I referenced with the photo bucket label is an ...original 6V positive ground..style wiring for your set up. Just to add in the original configuration the L terminal feeds power to the ignition switch and lights. Since the generator is not there in your case it may be possible that the regulator is not there. I’m not sure if it mounts on top of the generator like it does on an H. Point being with no regulator if you want to temporarily run your tractor you will have to connect the Bat and L terminal wires together some way or find another path to supply 6V negative to the ignition switch. Possibly what Supper99 is referring to is in the linked post in the reply by KenB there is a link to BobM wiring diagrams, in that link there is a diagram to wire a tractor 12v negative ground using a Delco 10SI alternator.

It was "originally" 6 volt positive ground. If properly configured either 6 or 12 volt, positive or negative ground would now be "correct" for operation.

"How does a positive ground system work because that stumps me. You don’t actually ground the positive battery terminal to the chassis or do you?"

Yes. That is what "positive ground" means...the positive terminal of battery is tied to frame ground, and negative terminal is the hot post. With "negative ground" the negative terminal of the battery is tied to frame ground and the positive terminal is the hot post. Either configuration will work equally well with a generator if regulator is matched polarity and the generator is polarized accordingly.

Unless specially modified common alternators are negative ground.

The battery does not have a "ground" post, it has a positive and a negative post. (Parts stores do not sell "positive ground batteries" or "negative ground batteries". "Ground" is a characteristic of the circuit, not the battery. All polarity sensitive devices must match the circuit configuration.

Switches and lights are not polarity sensitive.

Starter will turn same direction either polarity. With negative ground, the - post of coil goes to side of distributor, with positive ground the + post of coil goes to side of distributor.

Coil itself will work either polarity, but if coil polarity is reversed the spark plug polarity is reversed

Positive and negative ground is like right hand and left hand threads on a bolt. With the bolts the nut turns in opposite directions, with ground configuration current flows through the circuit in opposite directions.

One advantage to keeping an alternator is that you won't have to deal with reported poor and erratic quality of today's generator regulators.

Thanks so much!