Jim Shepard Posted February 5, 2012 Report Posted February 5, 2012 Don't know much about electrical stuff so, if this sounds juvenile, bear with me... I know (I think I do...) when converting to 12 volts one of the things to do is put a resister on the distributor to keep the points from burning. Since our flatties were still used after the introduction of 12 volt electrics, can't we simply rebuild the 6V distributor with a kit for the 12V distributor? Or, simply use a distributor from a 1956 or later flathead? Quote
deathbound Posted February 5, 2012 Report Posted February 5, 2012 No need to change the distributor, but you will need to change to a 12V coil with a resistor, whether it's built-in or not. Quote
NiftyFifty Posted February 5, 2012 Report Posted February 5, 2012 You can run your 6v coil from what I remember but you must put in a resistor no matter what. If you ask for one from a mid 60's Chrysler vehicle their easy to come by and cheap. I put a new coil in just to clean up all my electrical, but I could have used my old one. Quote
mechresto Posted February 5, 2012 Report Posted February 5, 2012 Jim Any internally resisted 12v coil will work, '60's '70's GM. For the fuel gauge, a voltage reducer will be required, radio shack has 'em. For the heater motor, replacement is the easiest, if you can find a motor that will bolt in, otherwise remodeling of the motor carrier will be in order. not a huge pain but a pain nevertheless. A word of caution however, if using the original wire harness with a 12v conversion, go over it with a fine tooth comb, any breaks or possibility of rub thru anywhere increases the risk of fire exponentially. Bryan Quote
NiftyFifty Posted February 5, 2012 Report Posted February 5, 2012 Jim Any internally resisted 12v coil will work, '60's '70's GM. For the fuel gauge, a voltage reducer will be required, radio shack has 'em. For the heater motor, replacement is the easiest, if you can find a motor that will bolt in, otherwise remodeling of the motor carrier will be in order. not a huge pain but a pain nevertheless. A word of caution however, if using the original wire harness with a 12v conversion, go over it with a fine tooth comb, any breaks or possibility of rub thru anywhere increases the risk of fire exponentially. Bryan X2. I found wires under the dash of my 50 that you would never think would rub, and others that when cut just turned to dust. It's a very easy truck to rewire just using colored rolls and connectors. Quote
OldDad67 Posted February 5, 2012 Report Posted February 5, 2012 Don't know much about electrical stuff so, if this sounds juvenile, bear with me... I know (I think I do...) when converting to 12 volts one of the things to do is put a resister on the distributor to keep the points from burning. Since our flatties were still used after the introduction of 12 volt electrics, can't we simply rebuild the 6V distributor with a kit for the 12V distributor? Or, simply use a distributor from a 1956 or later flathead? You can get a Pertronix unit and eliminate the points all together. But if you go to 12volts you will need a ballast resistor to keep from overheating your coil, or an internal resistor coil. I use the Pertronix system on all my cars, you keep the stock looks without having to mess with the points. Great system. Quote
Plymouthy Adams Posted February 5, 2012 Report Posted February 5, 2012 If you decide to go with the Pertronix..I would suggest that you heed their advice and go with thier coil..per their website seems most all failures are due to improper resistance of the primary system causing too high a voltage on thier device...do bare in mind that you also just cannot pop into any corner parts house for a replacement unit..and SOME applications require modificatio of your original points plate to the effect you cannot retrofit for a limp in. Quote
Jim Shepard Posted February 5, 2012 Author Report Posted February 5, 2012 No need to change the distributor, but you will need to change to a 12V coil with a resistor, whether it's built-in or not. Ok, so the resister is for the coil, not the distributor? Other than the gauges, lights and such, why does the 12V coil need a resistor? Did the originals have them? Quote
deathbound Posted February 6, 2012 Report Posted February 6, 2012 You can get a Pertronix unit and eliminate the points all together. But if you go to 12volts you will need a ballast resistor to keep from overheating your coil, or an internal resistor coil. I use the Pertronix system on all my cars, you keep the stock looks without having to mess with the points. Great system. What he said. I don't understand why, it's what I've been told. Quote
wallytoo Posted February 6, 2012 Report Posted February 6, 2012 i was under the impression that 12v coils are 6v with an internal resistor. a "6v" coil can be used in a 12v system, as noted by others above, by using an external ballast resistor. Quote
lugnut123 Posted February 7, 2012 Report Posted February 7, 2012 Somthing ealse if you change your truck to 12volt I believe you will need a resistor. But since my old truck was positive ground and I changed it to neg ground I had to switch the wires on the coil so the neg side went to the points. and the hot side from the switch went to the plus side. I believe I am right doing this. Quote
1941Rick Posted February 7, 2012 Report Posted February 7, 2012 Leave it like it is...just add a ballast resistor to the coil.... Quote
MBF Posted February 8, 2012 Report Posted February 8, 2012 When I did my conversions, and old mechanic (actually a certified FAA tech) told me to make sure that I switched the wires on the coil, that there would be a noticeable difference but I forget why he said that would make any difference. I didn't argue with him and did the swap, and on the back of the ammeter too. I don't drive my truck a lot during the winter, but I did put a ballast resistor on the blower motor for the heater, and on the dash mounted 6 volt fan. Been running both the 36 Plymouth, and the PH for several years like that now, and all of the motors still work fine. I don't think there's a need to do anything with the switch wiring-its just a gate . Mike Quote
OldDad67 Posted February 8, 2012 Report Posted February 8, 2012 When I did my conversions, and old mechanic (actually a certified FAA tech) told me to make sure that I switched the wires on the coil, that there would be a noticeable difference but I forget why he said that would make any difference. I didn't argue with him and did the swap, and on the back of the ammeter too. I don't drive my truck a lot during the winter, but I did put a ballast resistor on the blower motor for the heater, and on the dash mounted 6 volt fan. Been running both the 36 Plymouth, and the PH for several years like that now, and all of the motors still work fine. I don't think there's a need to do anything with the switch wiring-its just a gate . Mike The reason to swap the wires on the coil and amp meter is because of the original positive ground that your car had. If you had a 6 volt negative ground it would not be necessary to swap those wires. If that makes sense. I went to 12 volts on my 52 Chevy and did not have to swap any wires because it was originally 6 volt negative ground. I better shut up I'm starting to get confused. Quote
mechresto Posted February 8, 2012 Report Posted February 8, 2012 Ok, so the resister is for the coil, not the distributor? Other than the gauges, lights and such, why does the 12V coil need a resistor? Did the originals have them? The reason for the resistor, whether it be a ballast type or a built in is to lower the voltage at the points, in the case of a 12v system the drop should be down around the 9.6v range max. This is simply to prevent point burn, the higher the primary voltage, the greater the amount of premature burn. hence a 6v system does'nt need one. If you go with a 12v internal resisted coil and you suffer from hard starting and it's traced to the secondary voltage to low at cranking speed, then go with a ballast resistor and wire it to bypass the ballast during cranking (full 12v to the ign circuit) and return to ballast during run circuit (extra wire needed to the coil). after a few hours run time, examine your points carefully. lok for material transfer from one contact to the other, if none present then youre good to go, if you have transfer then the microfarad rating of your condenser will need to be raised or lowered dependant upon which way the transfer is. I have no idea why some systems tolerate the change over to 12v and some don't, the condenser shouldn't give a crap either way, but some do. Bryan Quote
Reg Evans Posted February 8, 2012 Report Posted February 8, 2012 Jim, I found this in the technical archives. http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=27103 Quote
Jim Shepard Posted February 12, 2012 Author Report Posted February 12, 2012 Jim,I found this in the technical archives. http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=27103 Thanks Reg. That helped quite a bit (I think...). Quote
Dennis_MN Posted February 13, 2012 Report Posted February 13, 2012 I considered the change to 12v mainly to power a modern radio, CB, and GPS, however, I spent $50 and bought a inverter to do all of that stuff and I left the functional 6v to do what it has done for the past 62 years. Do a search for inverter. Quote
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