Also, you must be sure there is no metal-to-metal contact of the two vehicles. Here's a slightly smaller "Positive-to-Negative Ground High-current Converter" for $70 from: Antique Automobile, 700 Tampa Rd., Palm Harbor, FL. Jack, all cubs prior to mid 1964 were 6 volt, positive ground from the factory. If either vehicle has dual batteries with cables of the same thickness, use either battery for the jump. This makes a parallel circuit. The two Shumaker float chargers I have will automatically detect if the battery is a 6 volt or a 12 volt and set itself accordingly. 1956 and newer became 12-volt, negative ground. The wires are color-coded: red is positive, black is negative. 1955 model year was still 6-volt, positive ground. If I try to jump start I do not want to fry anything. 1950 Ford 6 Volt System With A Positive Ground With No Spark … I checked my coil and its getting power .. then checked my points, i get a spark when the ignition is on and touched with a screwdriver but when its cranked over im not seeing any spark at all from the points when its going thru its cycle of opening and closing . may apply to others. #1 Disconnect the ground cable of the 6 volt battery. Make sure all lights, radio etc are shut off in the 6V car. 6 Answers. It wants a 6 amp fuse, so I suppose it's good for 50 watts output. We've got to quit saying, ... What a surprise unsuspecting owners must have had when they went to jump start their three or four year old 12volt POSITIVE ground '55 Packards with a 'normal' 12volt NEGATIVE ground vehicle!!!!! BP. The 6 Volt 10Si series alternator is great for converting old Ford tractors from generator to alternator charging. Yes, your 1946 John Deere A has a positive ground. Take a look at the diagram below. Can this 6-V positive-ground vehicle be safely jump-started by a 12-V positive-ground vehicle? Converting From 6 Volts To 12 Volts or Double Your Pleasure, Double Your Fun by John the Old Tractor Guy and llamas, his sidekick . I am so confused If my tractor has a positive ground 6 volt, should the cable from the positive post on the battery go directly to the starter ? Simply so, how do you jumpstart a 6 volt battery? If a vehicle has only one battery, just be sure to hook the cables up in the proper order. It is a 1-3/4 inch cube. To polarize a generator on a tractor having a Delco 12V negative ground system, attach one clip to the A … The only wiring is the Battery to the starter and ground with a "stomp switch" in the middle. Connect a jump lead from the positive terminal to the positive terminal on the 24-volt truck battery. I have my POSITIVE ground 6 volt engine turning over. cable off the battery go to ground and the neg. jump starting a 6 volt positive ground battery, Attach the jumper cables to the battery that has thicker cables. So the top of the 6-volt scale is the bottom of the 12-volt scale. STEP 1: Find Jumper Cables (Jump Leads) Read and follow the Safety and Handling Information on this website and with the jumper cables. You can jumpstart a 6 volt with 12 volts, but the safe way to do it is with the key off. Many of the old positive ground tractors were 6 volts. Connect 12V battery, start car, take jumper cable off ground and quickly stick the 6V cable back on before car stalls out. I am using one on a 1940 H with original 6 volt cut-out relay, positive ground system, and an identical charger on a 1940 M with 12 volt alternator conversion. You charge it like any other 6 volt battery - with a 6 volt charger. It turns over pretty slow even with the battery charger on it. If it reads between 7 and 8 volts, it's working correctly. 10Si Series 6v Alternator. Yes, note the ground cable (Key 12) is connected to the positive (+) terminal on the battery and the negative cable (Key 1) goes to the starting motor. 6 Volt Positive Ground Starter - 1963 Cub Attachment(s) by The Riot » Wed Dec 13, 2017 11:41 pm » in Farmall Cub. Positive goes to positive and negative goes to negative.