[AT] More Ford Jubilee Adventures

Steve Offiler soffiler at gmail.com
Tue Aug 11 18:45:50 PDT 2015


Just wanted to say there is a ton of good advice here.  Well done Howard.  

If I could add anything at all, I'd suggest replacing points resistance test with a voltage drop test.  This has two benefits.  One, most any volt meter even real cheap ones will handle it.  Two, it's a real world test done under the kind of current load the system actually works with.  

Engine off, roll the distributor cam so points are closed.  Connect meter set to volt range across the points. Meaning, one meter lead on the coil terminal that goes to the points, and the other to chassis.  Old analog meter, watch your polarity.  Digital meter if you're backward it just puts up a minus-sign, no big deal.  Now turn on ignition.  Current flows thru coil and points to ground.  If the points are good, voltage will be around 0.1 volt or less.  If they are bad, they're typically way higher, like a full volt or more.  This test is not usually ambiguous.  Good vs bad is very different on even a cheap meter.  

SO

Sent from my iPhone

> On Aug 11, 2015, at 7:01 PM, Howard Weeks <weeksh at att.net> wrote:
> 
> I don't claim to be any kind of "condenser" expert but here are a few 
> comments on the subject:
> 
> 1. Back in the early 50s, I worked weekends for an old car/tractor 
> mechanic. He checked condensers by using a kick test. Basically, he put 
> the subject condenser in series with a small amp meter and placed the 
> combination across a 6 or 12 volt battery momentarily. If you got a good 
> kick on the amp meter and then nothing, the cap was good. No kick meant 
> it was bad. Any continuous current meant it was also bad. Be sure to 
> discharge the cap by shorting it before connecting across the battery. 
> This test always worked for him.  I have an old piece of test equipment 
> here that also checks a cap in the same manner. Some people can do this 
> test with one of the older design ohmmeters. The new digital meters will 
> not do the test.
> 
> 2. I have been restoring antique radios in some form for most of my life 
> and I have a lot of both old and late model test equipment designed for 
> evaluating capacitors. Most of the ignition caps that I have checked 
> measured approximately .17 - .2 microfarads in capacity. The choice of 
> this capacity is a function of the coil design and if properly selected 
> by the designer, the system should run indefinitely and not pit the 
> points. If they pit badly, it is a sign that the coil and cap are not 
> properly matched or selected. Which side of the points gets pitted is a 
> sign of whether the cap is high or low in value for a particular 
> combination of cap and coil. I am not trying to say that they have to be 
> a "matched set" - just that a gross change in cap or coil type could be 
> a problem. Most of the old ignition reference books from back in the 20s 
> and 30s do a pretty good job of explaining how they work and how to test 
> them. I can't honestly say that I have ever found a truly bad condenser. 
> But I have had hell with the point resistance (don't know where they 
> were made)!
> 
> 3. When point are closed, they should measure less than 1 ohm - 
> preferably close to zero ohms ever time they close for the ignition to 
> work properly. If they measure 2 - 5 ohms, the system will either not 
> run or it will be very sick. Same for magneto or standard ignition 
> system. Many of the cheaper ohm meters will not accurately measure 
> resistances below a few ohms.
> 
> 4. The resistors that are in series with some coils are designed to 
> limit the current through the coils when the engine is running. The DC 
> current through the coils should be in the range of 3 - 6 amps or so 
> when the engine is running. RPM and dwell settings will affect the 
> amount of current to some extent. If a coil designed for a resistor is 
> run without one, it will run for awhile but the coil will overheat and 
> usually quit fairly quickly. Putting a momentary short across that 
> resistor when starting the engine would produce a hotter spark for 
> starting purposes.
> 
> 5. Pay some attention to the polarity of the coil connection to the 
> distributor. If you have a negative ground battery system, the "-" end 
> of the coil should be connected to the distributor. The "+" end of the 
> coil goes to the distributor if a you have a positive ground system.
> 
> Don't know if any of this spiel is useful to anyone but it accurately 
> describes my experience with Kettering ignition systems.
> 
> Howard in GA
> 
>> On 8/9/2015 2:30 PM, Mogrits wrote:
>> I don't disagree with you on anything you said, except the resistor has
>> been bypassed on my tractor and it uses a coil that needs no resistor.
>> Substituting for the new, correct condensor produces a spark. The new
>> condensor does not. So there is definitely a need to replace that
>> particular condensor.
>> 
>>> On Sun, Aug 9, 2015 at 2:13 PM, Ron Cook <ron at lakeport-1.com> wrote:
>>> 
>>> There is usually no reason to replace a condenser.  Starting problems
>>> with Ford N tractors can usually be traced to the resistor.
>>> And I certainly do agree on the crap that is sold these days being no
>>> good right out of the box.  I quit going to TSC years ago for that very
>>> reason.  So too, did many.  TSC closed their store in Sioux City.
>>> It has actually helped my generator/starter repair business a little.
>>> The do it yourself bunch have lost their cheap parts supplier, which
>>> really were not cheap anyway considering you always have to buy two or
>>> more to fix the problem.
>>> Ron Cook
>>> Salix, IA
>>> 
>>>> On 8/9/2015 5:52 AM, Cecil R Bearden wrote:
>>>> I went through the same thing with a fence charger 2 weeks ago.  Worked
>>>> all afternoon in 105 heat index to get wire up around yard to keep pet
>>>> bull in.  Had a good charger in a tool box next to the other elect
>>>> service at the South Barn.  It would barely spark.  Dug out the brand
>>>> new Zareba charger from TSC that had never been used, it had no spark.
>>>> Took the Harbor Freight solar one off the back fence and it was shot.
>>>> Took the Parmak solar fencer off the divider fence for the horses and it
>>>> worked!!!
>>>> 
>>>> I certainly hope the pertronix system fixes your problem...Condensers
>>>> are being made in China or some other 3rd world country, so quality is a
>>>> problem...
>>>> 
>>>> Cecil in OKla
>>> 
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