Rodney Bullock Posted June 7, 2009 Report Posted June 7, 2009 The coil can be bad even if I get spark at the points with the ignition "on" right? That just means that there is fire on the ignition side right? :mad:just when things get to good they get bad. Sleep will be hard tonite. Quote
Frank Elder Posted June 7, 2009 Report Posted June 7, 2009 If the coil is too hot to touch, it is weak and will not deliver the proper amount of spark. It should only be warm.....just read this here not too long ago, hope it helps. See ya in the movies:D Quote
47dodgepu211 Posted September 30, 2009 Report Posted September 30, 2009 I have a new 12V coil in my old dodge flathead with 12 volt system. I just noticed that while working on my wipers with key on, coil became too hot to touch after about one hour. I don't think coil has built-in ballast. What can I do about that If I put a dropping resister in series (1.2 ohm ceramic) will that make car hard to start and affect performance? Thanks, Quote
greg g Posted September 30, 2009 Report Posted September 30, 2009 Wire the wiper to the accessory terminal. that will power the wipers without energizing the coil. You can also hand rotate the engine so the points are open and then the coil will be out of the circuit. Quote
Plymouthy Adams Posted September 30, 2009 Report Posted September 30, 2009 (edited) I have a new 12V coil in my old dodge flathead with 12 volt system. I just noticed that while working on my wipers with key on, coil became too hot to touch after about one hour. I don't think coil has built-in ballast. What can I do about that If I put a dropping resister in series (1.2 ohm ceramic) will that make car hard to start and affect performance?Thanks, it does sound as if the coil is running on straight 12 volts..not only is that hard on the coil, it is also hard on the points/condenser in the distributor. The fact that it has not got to the point that when heated it has shut down is a miracle..The dropping resisitor is matched to the internally reisistance of the coil and the parts house should have the reference to the recommended resistor per coil listing. The use of a GM coil with internal resistor would be another choice..it will taper its voltage, temperature sensitive..so no matter the route you take, do get one or the other..if you get the resistor in line do be sure ohm value is correct to by pass the resistor when in START mode...through the reisistor in RUN mode.. the ohm value is necessary to keep the coil amperage load proper to ensure full saturation and maintain secondary spark..most times the difference is for the number of cylinders you are running as this is the regualting factor for dwell time..if you do not have an amp meter to accurately check the current draw on the iginiton system ..you can be right on, little low in amps, little high in amps where the high is the heat...basically there are about 3 resistors in the mopar lineup excluding the super low ohm model for full out race with MSD application..one will suit your needs..get a slant 6 setup and you should be right first time.. Edited September 30, 2009 by Tim Adams Quote
Joe Flanagan Posted September 30, 2009 Report Posted September 30, 2009 Rodney, Don't know if this helps but when this happened to my truck a couple months ago, I was getting a spark even though the coil was bad. Do you have a volt/ohm meter? I think the manual might have a test you can run on the coil. Which car is having the problem? The other twist in this is that even though my coil tested bad, it was within specs some 24 hours later. I replaced it with a new one and have not had a problem since. Quote
grey beard Posted September 30, 2009 Report Posted September 30, 2009 All the advice here is very good - and all correct. What you want to remember is that when your engoine is shut off and at rest, there is always the possiblilty that the ignition points are in the closed position. For this reason, it is an excellent idea to NEVER leave your ignition switch in the ON position for very long at one time. By so doing, you can burn both the contact points and mebby' even the coil, if it gets hot enough. In point or fact, you can tell when your points are closed just by looking at your dash ammeter gauge when you turn your ignition switch on. If the points are closed, the meter will jump to the discharge side. If the meter does not move at all, go ahead and work with the switch on - no damage will occur - that is, if your ammeter gauge is working. Good Luck Quote
greg g Posted September 30, 2009 Report Posted September 30, 2009 Dizzy cam roulette, the likely hood of having the engine stoping with the points on the high part of the cam is pretty slim, as one of the pistons would likely be coming up on compression stroke (which is probably what makes the engine stop rotating) so it will stop before TDC and leave the points on the flat (closed) part of the cam. The house if gonna win more times than not. Quote
claybill Posted September 30, 2009 Report Posted September 30, 2009 wonderful...i love listening to this stuff....most of it goes flying swiftly over my head but i am intrigued and do retain a little. usually just enough to ask a question down the line. amazing,... the kowledge here!! thank you. bill Quote
47dodgepu211 Posted October 6, 2009 Report Posted October 6, 2009 Yes indeed my coil does not have internal ballast. Because of overheating spark is about 1/2 inch to plug but color is blue-orange. I'll get a new coil with built in ballast and see how that goes. As cold weather sets in, I will know soon enough. Good comments from all!!! Quote
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