12 volt kit resistor

I recently purchased the 12 volt conversion kit for my 1945 2n. with a little adapting I got it to work. Question is that the kit comes with a resistor IRD600 I believe. In the wireing plans it shows how to hook it up and says IF NEEDED. How do I know if I need it? or should I just hook it up anyways? The resistor on the tractor is only 2 years old. please help, I have to get this running before it gets to cold out.

Did you buy a 12 volt coil or a 6 volt coil?
If you bought a 12 volt coil you would only need the original ballast resistor.
If you're using the 6 volt coil you would need to install both.

HTH

Andy........would it surprize you to learn resistors are just like light bulbs, they either work (light) or they don't (dark). In otherwords, a 2-yr old resistor ...or... 50-yr old; donna matter age, it either works ...or... it don't. (tip: hottcha-hottcha, burnie-burn) Simple, eh?

Yer 6-volt 1945 2N, has the weird 4-nipple dizzy with a 1-wire squarecan coil. It is powered thru the "infamous ballast resistor" from the ignition ON switch. And here comes the confusion, either the original 6-volt or the modern 12-volt squarecan coil needs the MANDATORY "infamous ballast resistor". NO ARGUE!!!

The cheap "Bubba" 12V conversion uses the original 6V squarecan coil ...plus... a 12V-to-6V converting resistor. (what you are calling "IRD600") We recommend squandering yer money for the modern 12V squarecan ignition coil ...and... the mandatory "infamous ballast resistor" ...and... NO USE the IRD600. Understand???

Now you have exchanged the 1-wire 3rd-brush 6-volt genny with roundcan cut-out for yer 3-wire 12V-alternator with idiot-lite. Yer alternator has 2 slip-on terminals and a BIG alternator 12V output stud. Connect the BIG stud with about 3" of wire to the #2 slip-on. (voltage sense) Now connect yer #1 slip-on (excite) thru the idiot-lite to yer ignition switch ON terminal. Without the idiot-lite (I use a common trailer clearance lite) you can NOT turn yer engine off because of backfeed volts from INSIDE the alternator going to yer sparkie coil. .........Dell a 12V advocate for the right reasons, who knows 8-ways to convert to 12V and they all work the first time

OK, thanks guy's. I have the 12volt coil so I will forget the second resistor.

If you converted your tractor over to an alternator the resister will bolt to the back of it. If not used on the alternator in the alternator circuit the alternator will continue to feed the ign system and when you want to shut the tractor off it will keep running instead.