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My 1952 F-1 for some reason the coils keeps going bad. The first one came from Advance Auto which was cheap ($15) and I figured that was not unusal.The second one came from NAPA at about ($ 50).Now I am starting to wonder what is going on! NAPA is going to replace it,because I only had it in about two weeks!I thought I had fuel problems but it is the coil breaking down.The truck would sat and idle good, but every time I try to rev it up it acts like it is starving for fuel, but it is the coil! Does anybody have an idea of what is going on? Truck is 1952 F-1,flathead with stock 6-volt system.Thanks,Russell
Guess you’re stuck with me, real experts should be along presently;
I wonder if it is the coil? When you put the new one on it runs fine and then (a couple of weeks) will idle but not rev, right?
Two things come to this old feeble mind,
I wonder if you are getting a true 6 volts to the coil, maybe check the inlet wire with a volt meter, especially when it acting up, jiggle the ignition switch, under dash wiring and your left foot (never know)
Something that is common is the ignition points lead wire under the distributor advance plate (if equipped) idles good, revs up and as the plate advances (moves) if there is a bare spot it shorts out and runs rough and will not rev?
Is it literally eating coils? Has the wiring throughout the truck been replaced? I suspect that might be where the problem lies. I run a Pertronix ignition system and a 12 volt coil on my 52 F-1 still with the 6 volt positive ground system and it works great and haven't had any problems with it so far. It's been installed on my truck for the past 3 years.
The coils they make today are garbage for the most part. I bought two that were brand new, and they did the same thing. They work fine when you start up the truck then as you drive they start to (as you said) cause the truck to sputter and pop, then eventually they die...here's why:
Those coils are oil filled as insulation. Most of the ones made today are either not filled enough or the thin oil does not adequately insulate. As the truck warms up the coil gets warmer and warmer and eventually gets too hot/dies.
First, make sure you have the right ballast resistor inline going to the coil. While these are normally to protect your points, if you don't have one or it is the wrong one, it may affect the coil.
Second, get a Pertronix "Flamethrower" coil that is epoxy filled not oil filled. I did that and no more problems!
I'm running a Schuck's/Kragens/Checker "universal" coil that was about $12, has been in there for more than 3 years and no problems, either on normal points or on a MSD system. The only difference is that it is a 12v unit. I don't doubt newer coils don't meet some lofty standard but this is not rocket science. I agree with John, something else is likely the problem. I'd check the condenser, which are known to be a problem quality-wise. The behavior where it runs OK at idle, and falls down under load, sounds like when the vac advance kicks in (or doesn't???) there is a problem, and that could be the wire under the points plate flexing and grounding.
AFAIK the 6v systems didn't use a ballast. But in the period 48 - 53, some of the cars did use them, trucks didn't. None of the wiring diagrams I have show one for 51 - 52.
I do not have a ballast resistor.It tells on the coil that this is not needed.The coil is the problem for sure,because when I switch coils the problems goes away.
I'll pass on two items I was instructed to do when I was a teen driver in 55-56. I was told the coils that had the wires in the 5 & 7 o'clock position should be mounted horizontal position with the wires at the bottom because the inside parts were not in the center and not full of oil would leave windings uncovered and would burn them out. Others said to mount the coil up, off of the engine or on the firewall as engine heat sometimes killed the coils. I don't remember if there was only one brand of coils, or more choices. This may be all bull. As a teen you just absorbed information and didn't always ask to many questions. chuck
I do not have a ballast resistor. It tells on the coil that this is not needed.....
That almost certainly means it already has a ballast resistor inside the coil. Is it a true 6v coil? I mean, they looked up your year and it said to use that piece? Do you have the NAPA number so we could see exactly what it is?
Here are national brand name parts that should be the ticket, at Checker/OReilly:
I had one UC14 (Standard) that went bad and one IC7 (Echlin) that when bad and they gave me another one.It was only in for about three weeks before it started breaking down.The echlin is what I have in now.So far so good!It sells for about $50 from NAPA.
So many of these parts are "off shore" and often fail. That's one more reason to find out the problem through troubleshooting rather than throw new parts at it hoping to find the right one. So many times we find the owner put a bunch of new parts trying to find a problem and once we locate the original issue we have to go back and put some of the old parts back on to get it running since one of the new whatever was bad.
Hope your newest coil last, it is very aggravating to keep "fixing" the same issue over and over and GOOD parts are getting harder and harder to get.
Larry
You might check to see if it's getting hot while running. What gap are you running on the plugs? Are you using resistor-type wires? Gap should be only .025".