Author	[Modern View]
Bud W 02-03-2013 19:01:13 70.242.114.188 Report to Moderator	But Jim where in the heck does the resister go? I can't find one on this tractor or any of my others ( 2 Cubs and a SMTA ).Bud [Reply]   [No Email]
The tractor vet 02-03-2013 20:24:48 75.19.114.143 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-03-2013 19:01:13   They WERE NOT USED on six volt systems , I H never changed coils when they went to twelve volt they added the resistor into the systems . when they went to the twleve they put the resistors next to the coild and like said above the BLACK wire hooks to it and there is a WHITE wire coming from the R post on the starter tha bypasses the resistor to give the coil a shot of straight 12 for a hot start when you press the starter button . Once you let off the starter button all the juice then goes thru the resistor and the 12 volt feed is cut down to 6-8 volts to the coil. to save the coil and the points. You can use either a GM resistor or one off a Mopar that has the two terminals They did not go to this till the 460-560 . [Reply]  [No Email]
Bud W 02-04-2013 11:09:25 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to The tractor vet, 02-03-2013 20:24:48   Vet So as long as I replace my 6 volt coil with another 6 volt unit no problem ? I was hoping I could eliminate the 12 to 6 volt resister before the coil and just install a 12 coil but sounds like your saying if I do that I need to add another resister somewhere in the coil circuit ans since I really don't know how to do that I better just stay 6 volt on the coil. Correct?? [Reply]  [No Email]
The tractor vet 02-04-2013 12:47:59 75.19.114.143 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-04-2013 11:09:25   Well i am sorta in the dark here , What tractor are you working on for one and for two is it a six volt now or is it a 12 volt . ?????? IF it is still 6 volt then no resistor is needed with a six volt coil. IF it WAS a six volt system and has been changed to twelve then if your running a stock coil from the six volt system then it needs a resistor . If you have replaced the six volt coil with a twelve volt coil it should say on the side of the coil if it DOES NEED a resistor or not . A couple years ago i broke down and switched my S/MTA over to 12 volt and all i added was the resistor . It is installed behind the STOCK coil that the S/MTA came with , and all i had to do was take the ing. wire off the coil and hook it to the resistor and make up a short jumper wire to go from the resistor to the coil. [Reply]  [No Email]
Bud W 02-04-2013 15:26:56 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to The tractor vet, 02-04-2013 12:47:59   Sorry , I seem to have a problem in my explanations. What I have is a 52 Super C that has been converted to 12 volts ( 12 volt battery , 12 volt alternator and a 12 to 6 volt resister in the circuit to the coil. The tractor will not start and I suspect a bad coil since I can't get spark to jump from the coil to ground or from the plug wires to ground. I thought if I was going to buy a new coil why not just go with a 12 volt coil and eliminate the 12 to 6 resister.There is an original looking 12 volt coil in the parts area of this site but they can't tell me if I need a resister with it so I'm stumpt. HELP [Reply]  [No Email]
Janicholson 02-04-2013 15:44:06 74.60.94.18 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-04-2013 15:26:56   NAPA number MPE IC 10SB Less than 25$ Jim [Reply]  [No Email]
Bud W 02-04-2013 16:39:48 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to Janicholson, 02-04-2013 15:44:06   I just looked up the NAPA item you mentioned and see your trying to save me some bucks on a coil. Thanks but I would gladly give someone $300 just to get this @#@ tractor started.I'm hung up on the darn external resister. I want a 12 volt coil with the wiring connections on one end and the distribtor output on the other end like the original equipment. I feel like I've wasted a lot of your time and others and I'm just too dense to understand this darn resister issue.If I buy the 12 coil off this site do I need an external resister and if so how do I install it?? [Reply]  [No Email]
Bud W 02-04-2013 16:24:48 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to Janicholson, 02-04-2013 15:44:06   So I eliminate my current 12 to 6 volt resister , install a new 12 volt coil and add the new resister-right? Is this new resister installed just like my existing one ie in the line to the coil input?Thanks [Reply]  [No Email]
Janicholson 02-04-2013 16:57:24 74.60.94.18 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-04-2013 16:24:48   If (and only if) the resistor you have is good should you use it. If it has about 2 ohms of resistance, it is good. Use it. If you aren't sure how to read ohms, use a test light as follows: remove the wire from the coil connected end of the resistor. Hook a wire from the battery positive to the other end of the resistor. use a test light to ground to the disconnected end of the resistor. If it lights the resistor is good. Use it. If it lights only on the battery connected end and not the other it is bad, Get a new one as specified above. I would replace the coil with the one above. It is fine for the use of the tractor and was chosen for appropriate values not price. Jim [Reply]  [No Email]
Bud W 02-04-2013 17:33:17 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to Janicholson, 02-04-2013 16:57:24   Jim Sure wish I could talk to you directly.Are you saying the resister that I have that protects my 6 volt coil from my 12 circuit is the resister that you have been talking about all along? Why would I leave that in the circuit if I install a 12 v coil? Bud [Reply]  [No Email]
Janicholson 02-04-2013 18:31:53 74.60.94.18 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-04-2013 17:33:17   MAPA number MPE IC 14SB is 12v no resistor needed. If you buy this coil it hooks directly to your ignition switch on the + side and to the dist on the - side. No resistor is needed. It will be OK Jim [Reply]  [No Email]
Bud W 02-04-2013 19:15:31 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to Janicholson, 02-04-2013 18:31:53   Jim I'm going to do it. If this doesn't get me going I may be back to you. Thanks a bunch as always Bud [Reply]  [No Email]
John G. Hasler 02-04-2013 17:52:22 174.124.25.60 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-04-2013 17:33:17   If you install a 12 volt coil of the type that has an internal resistor then you should remove the resistor that you are using now. [Reply]  [No Email]
Janicholson 02-04-2013 18:28:12 74.60.94.18 Report to Moderator	Re: Coil External Resister in reply to John G. Hasler, 02-04-2013 17:52:22   Dear John With no disrespect, there are no internal resistors in coils. The 12volt for use with no external resistor does not imply that there is an internal resistor. There is not. It is just wound such that it can operate on full 14.2 volts of an operating charging system. Bud's tractor has a 6 volt coil of unknown operational status. (we think it is bad) he needs either a new ballast resistor, and a new coil, or a new coil only. If he purchases a 12v No external resistor required coil he can dispense with the ballast resistor all together. That is part number MPE IC 14SB (no resistor required 12v. Jim [Reply]  [No Email]
John G. Hasler 02-04-2013 18:52:54 174.124.25.60 Report to Moderator	Re: Coil External Resister in reply to Janicholson, 02-04-2013 18:28:12   > there are no internal resistors in coils. The > 12volt for use with no external resistor does > not imply that there is an internal resistor. > There is not. It is just wound such that it can > operate on full 14.2 volts of an operating > charging system. I know that, but the manufacturers often describe them as if they do have an internal resistor. It"s simpler to accept that description than to explain that they are wound with very fine wire. > If he purchases a 12v No external resistor > required coil he can dispense with the ballast > resistor all together. That"s what I thought I said. [Reply]  [No Email]
Heat Houser 02-03-2013 20:02:34 192.43.65.245 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-03-2013 19:01:13   What tractor are you dealing with? My JD4010 gasser has the resistor as part if the ignition switch. My 560 farmall has it mounted by the coil. My B farmall does not have one as it is a 6 volt system. [Reply]  [No Email]
Bud W 02-03-2013 20:09:32 70.242.114.188 Report to Moderator	Re: Coil External Resister in reply to Heat Houser, 02-03-2013 20:02:34   52 Super C [Reply]  [No Email]
Janicholson 02-04-2013 09:09:24 199.17.6.208 Report to Moderator	Re: Coil External Resister in reply to Bud W, 02-03-2013 20:09:32   Mount it on the same bolts that hold the coil. The one I indicated has a nice mount that works. On a Super C there is no bypass. If you really want the bypass you need to remake the starter to use a relay and small push button. Jim [Reply]  [No Email]