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yes ordered a set of wires and also going to replace the coil and figure out how to add the resistor. While I have to check the voltage, it appears to me that the coil has been receiving 12 v all the time and probably why it is so freaking hot! you can cook a chicken on it after just 40 min drive.
You need to find out where the 12v supply is currently coming from. It should go to the starter solenoid to supply 12v to the coil only during cranking. After it starts, voltage is supplied by the resistance wire.
I wouldn't replace anything until you correct the coil wiring.
Last edited by 71 Green 454; Aug 7, 2021 at 04:54 PM.
You need to find out where the 12v supply is currently coming from. It should go to the starter solenoid to supply 12v to the coil only during cranking. After it starts, voltage is supplied by the resistance wire.
I wouldn't replace anything until you correct the coil wiring.
I agree, That resistance wire if it's connected to the coil positive could be grounding out at its' other end somewhere, and that will cause you problems.
I certainly have no clue on coil and resistor but your detective work is valuable..if one wire doesn’t fire and others do…that coil aint gonna know which one not to fire?
OK, changed the plugs ( NGK). When car was cold it runs great. Drove 40 mins on highway ( 85F here in NJ). the car started to stumble, sputter about 30 mins in and ran rough and hesitated, slight bucking. While all the mechanics swore the wires were fine I decided to pull a few when I arrived home with the engine still stumbling. With engine running, I pulled #1 wire and there was no change in the rough idle at all. ... hmmm... So i checked the wire for spark, and Nothing.! . Then pulled #3, it had a good spark. Here is a photo , It has a napa coil that is asking for a 903 external resistor... I cannot find the external resistor ( Napa 903) , where the hell can it be ? The coil was super hot for an hour even after stopping the engine. I assume this is because improper voltage into the coil. OK so seems to me the people that worked on in screwed up the resistance wire ( not connected and just dangling in the air) and there is no external resistor on the coil to be found. ... comments welcome. My neoghbor told me to just convert to an MSD unit 6L ? Are MSD better ?
Also the car was running about 15 F hotter than usual, coil with resistor wire hanging off... and i cannot find any external resistor
Is the wire connected to the negative terminal of the coil running to the points in the distributor?
Is the braided wire in the picture one or two wires?
Have you looked at the small terminals on the starter solenoid and do they both have wires connected?
Thank you everyone for your suggestions.. So I finally figured out part of the issue. After changing the plugs and wires, I still had a engine mis. Now remember it had all new cap, rotor, points, condenser prior with only a few hundred miles on them. It turns of that the #2 port in the distributor cap had no spark. So I slapped on a new cap, rotor and the engine mis is gone at idle. However, it is still stumbling a bit at low RPM acceleration ( slight bucking) and this clears up above 2500 RPM. I still know that my coil is not wired correctly as it has only a 12v lead to it . I need to have it rewired from the starter solenoid for instant 12 v on starting and then for the second resistor wire to take it once it starts for the proper lower voltage. I cannot find the resistor wire or any ballast resistor on line or in stores. Any idea where I can find it ?
I think the car is still acting up a bit because the points may be slightly burnt from the coil issue above.
Would appreciate a view if I should just replace this ignition system with a good MSD system and be done with it. I have this on my other car that has a 427 and it works great so far.
Driving 47 years and never broke down but with this 1972 I have broken down 6 times in 6 months in Miami (hot and so many crazy drivers), SO sick of this so think I will replace older parts as well that are currently ok but will likely breakdown in the next 5K miles. Figured a new carb is in the future too.
I wouldn't upgrade until you figure what's wrong. You can check the points with a dwell meter. Is your vacuum advance working? Is your initial timing correct?
This is pretty basic stuff that you can/should do before replacing anything.
Thank you... Yes will do the basics.. What makes me crazy is that all the prior issues were weird and unusual and coslty. Agree this seems to be now, basic issues. I have to find out more about the ballast resistor and where to find them.
I do have a sneaky feeling the advance is not working correctly. On Weds it will be in a good shop in NJ... I have to tell you finding good shops in Miami is very hard. Plus all these young mechanics know little about older cars..
If your points/dwell is OK, I wouldn't worry about the resistor wire now. That not being hooked up will not cause the problem you are describing, All it would do is reduce point life.
Although it appears, based on your photo, that the white braided wire IS the resistor wire.
thanks... I was sensing that the coil was gettting very hot given the 12 v coming into it all the time. I am hopefully a few days from being back to driving happy again!
