Author	[Modern View]
Dave in DE 08-16-2012 20:20:26 137.183.232.23 Report to Moderator	I'm in the process of converting My 48 8N front mount to 12v using a kit I perchased. the included instuctions say "included resistor can be used, IF NEEDED with the included 12volt coil". there wiring diagram shows it wired one of two ways, eather using their resistor in series with the exisisting old 8n resitor or using the existing 8n resistor as stand alone. does not state how to determine if you need to use their resistor. never found one wired this way usually it only uses the resister that comes in the kit any idea's? will the existing 8n resistor work for one of these square 12v coils standing alone? what should the final voltage be at the coil when going to a 12volt system using square 12v coil? [Reply]   [No Email]
W_B 08-20-2012 10:29:58 155.188.247.23 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Plane Bart, 08-16-2012 20:20:26   Dell, that's what I thought. My meter is pretty good and will measure low resistance, but maybe I don't have the right scale selected. It goes from 0.00 across the resistor to 1.00 if I touch the two meter leads together. I've measured things that had less than one, like through my old resistor sparkie plug wires, changed to copper after they showed in the range of .4 to .5ish. Thanks. [Reply]  [No Email]
JMOR 08-18-2012 20:37:30 72.181.173.171 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Bruce (VA), 08-16-2012 20:20:26   Quoting Removed, click Modern View to seeNo he is not, nor the engine running voltages either. [Reply]  [No Email]
NOXJohn 08-17-2012 08:55:48 184.5.164.213 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Dave in DE, 08-16-2012 20:20:26   A 12 volt square front mount coil should have a resistance of around 2.5 ohms. This is to low to run without an additional resister. If hooked up with out an additional resister you will have to much current going through the coil and it will over heat and burn up. The original ballast resister used on the front mounted distributor N tractor has an initial cold resistance of a little over 1 ohm. It heats up after the tractor runs for a little while and the resistance increases to about 1.5 ohms. If you use this original ballast resister the lower initial resistance will give you better starting but be sufficient to hold the coil current down to 3.5-4 amps and not burn up your coil. I believe the resister included in the kit is only used in series with the original ballast resister when using the original 6 colt coil when converting to 12 volts. [Reply]  [No Email]
W_B 08-17-2012 08:03:38 155.188.247.18 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Dave in DE, 08-16-2012 20:20:26   What should the resistance measure be through a ballast resistor, cold? On my 9N it measures 0 cold and still 0 after about 10 minute warm up. Not enough warm up? Also what should the resistance be though the front mount coil? [Reply]  [No Email]
Dell (WA) 08-17-2012 09:09:24 97.113.108.50 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to W_B, 08-17-2012 08:03:38   W_B........would you believe yer "infamous ballast resistor" should NEVER have 0-ohms (hot or cold) It should test about 1.7-ohms cold and about 2.7-ohms hot. Surprizingly enuff, most consumer ohm-meters are NOT very accurate measuring low-ohms. More better, read the volts at the top of the 1-terminal squarecan ignition coil. Should read about 3-volts when cold and about 2.5-volts when hot and running. ........Dell, yer self-appointed sparkie-meister and retired electronics calibration engineer [Reply]  [No Email]
NOXJohn 08-18-2012 13:57:02 184.5.164.213 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Dell (WA), 08-17-2012 09:09:24   Dell are you sure about those ohm resistance values for the ballast resister? [Reply]  [No Email]
Charles Krammin 08-17-2012 07:58:46 69.174.184.231 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Dave in DE, 08-16-2012 20:20:26   Royse, Without knowing the internal resistance of your coil, I would recommend you use either the existing "ballast resistor" or the ballast resistor provided, and if you have starting problems, then jump accross the terminals, of the ballast resistor, therby taking it out of the system. This would give you the best protection, of coil and points and you can come to your own solution by starting and running characteristics. As an example on my Ford 600 round can coil (3.25 ohms, internal resistance, from a JD 45, 12 volt combine,measured with a "didital ohm meter" with no visible ballast resistor) I used the .7 ohm "ballast resistor" in series with the coil. Their is a slight difference in cold winter starts, but good in all other weathers. If I wanted I could run without the ballast resistor. On my 2N 12 volt, front mount, 6 volt coil, I attach a 12 to 6 volt dropping resistor and a "ballast resistor" in series and have good results. Hope this answer your question without stating a lot of numbers. Charles Krammin SW MI [Reply]  [No Email]
Royse 08-16-2012 20:36:19 69.36.49.151 Report to Moderator	Re: 8N front mount 12v conversion ?? in reply to Stockdale Dave, 08-16-2012 20:20:26   You need to use the original ballast resistor if using the square front mount coil. If you have a 12 volt square coil, it "should" only need the original resistor providing the internal resistance of the coil is high enough. 6 volt coil will need the extra resistor. I don't want to quote numbers from memory, but there are a lot of posts on this in the archives if you have a minute to search. Let us know how it goes! [Reply]  [No Email]