Jim Shepard Posted February 26, 2013 Report Share Posted February 26, 2013 Is there a test to determine whether a coil (otherwise unmarked) is a 6V or 12V? Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 26, 2013 Report Share Posted February 26, 2013 Most all coils are 6 volt unless marked otherwise. Have you converted to 12 volt? if so any 6 volt coil will work as long as you add a resistor. Some 12 volt coils have an internal resistor but they are normally marked as such. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted February 26, 2013 Report Share Posted February 26, 2013 most coils that are designed fpr 12 volt, have a dropping resisitor built into the coil itself...(GM) these often have a hollow section at the bottom of the coil..these coils also read approx 3.4 ohms...most other coils are desined for 6 volt and 12 with dropping resistor is external and have a ohm rating of approx 1.7 Quote Link to comment Share on other sites More sharing options...
Jim Shepard Posted February 26, 2013 Author Report Share Posted February 26, 2013 I have a coil that I think is 12V, but I'm not sure. I'm converting to 12V and would like to use a 12V coil, preferably the one I have. How is the ohms test done? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted February 26, 2013 Report Share Posted February 26, 2013 (edited) you must have a good accurate volt ohm meter and read the primary windings... lot of folks did not understand the concept of the resistor added and that the coils stayed the same when going to 12 volts..the same with meter movements of the dash gauges..the movements kept the same electrical funtion/design and the voltage difference was addressed through a CVR.. Edited February 26, 2013 by Plymouthy Adams Quote Link to comment Share on other sites More sharing options...
Scruffy49 Posted February 26, 2013 Report Share Posted February 26, 2013 Coils are supposed to be marked for voltage and whether or not they need an external ballast. Most 12v old type Mopar and GM need a ballast resistor, Ford coils generally do not. The 12v coil on my 230 just says 12v. And has a condensor on the - side of the coil wiring. It will be replaced with a NAPA part number IC64 or Tractor Supply Company equivalent, 12v with internal regulator. Your points and condensor can be left stock, not voltage sensitive. Add a headlight relay, and a Runtz transistorized voltage reducer to your fuel gauge. Rebel Rodz issue 17, April 2010 has a good conversion article. Maybe they have back issue articles archived online... Quote Link to comment Share on other sites More sharing options...
Jim Shepard Posted February 26, 2013 Author Report Share Posted February 26, 2013 My coil is pretty scratched up and any identifying labeling is long-gone. I was under the impression that the purpose of a resister was to "save" the points and condenser. When performing the ohms test, how do I hook up the meter? Anyone got a diagram/photo? Thanks... Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted February 27, 2013 Report Share Posted February 27, 2013 Pos to Pos,neg to neg Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted February 27, 2013 Report Share Posted February 27, 2013 yes to a degree you are right as it is to limit the current going through the coil...the coil is turned off and of if you will by the opening and closing of the points to ground....if not used with 12 volt you will quickly overheat the coil and go to ignition failure...odds are when cool it will work again but not a good idea to cycle it like this as you start breaking down the insualtion of the windings as you are reading windings of a coil the polarity of the test leads with the meter is of no consequence..as long as one lead is one terminal and the other lead is on the other terminal..when you start testing items with a PN junction (diode/transistor) then polarity will be in play... Quote Link to comment Share on other sites More sharing options...
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