JD Positive ground , I've been Thinking

[Anonymous-0]

A few posts back there was discussion on JD positive ground. I bought a Jd 55 COMBINE last fall with a 217 engine' 12 volt Battery was in, started it up ran OK Checked amp gauge and it showed discharge. Checked the battery and noticed that it was hooked up to negative ground. Was told it was OK to use it like that because the polarity in the generator would now be reversed and to just change the AMP wires around.Then it charged positve amps. Used it on 45 acres of Wheat and seemed OK except some times it would miss and loose power and sometimes even stall. What Im wandering in a case like that should the wire to the coil also have been reversed?

 

[Bob]

With (-) ground at the battery, the (-) terminal on the coil needs to go to the distributor points/condensor.

Having it backwards will lesson the effectiveness of the spark at the plugs perhaps 20%, POSSIBLY causing SOME mis-firing at high speeds/under load.

It is NOT causing the engine to stall. Your actual problem sounds like a fuel supply restriction or water/debris in the carburetor.

 

[Blackhole49]

I thpugh all 12 volt was negative ground. I though only 6 volt was positive. Are you sure the alt. is working?

 

[rrlund]

55 combine would have had a generator,not an alternator. Deeres were positive ground through most of the 60s.

 

[John T]

The coil will still fire the plugs at reverse polarity but its not as efficient and theres less spark gap energy. She can charge at either polarity so if thats all working simply match the coils polarity to your combine. For Neg ground its lil - wires to distributor but at Pos grnd its + wires to distributor. The combines I had were bad to get fuel system clogs like the line or sediment bowl or filter or carb that caused lots more problems then I had with ignition.

John T