Good analogy! Want another one? Connect the jumper cables bass-ackwards and observe a 20-24V DC spark—vs. connecting them up correctly and still get a 1-6V spark. When I’ve done this, I seemed to get too busy undoing my action to see which direction the spark jumped. Arc welding is the same phenomenon with the ark melting metal and pulling it from the electrode to the joint. I’ve always admired the hand-eye coordination it takes for a welder to make a proper joint. Rich Barber, Pipeliner Brentwood, CA From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Mark Souders MRS954@xxxxxxx [Chrysler300]
Sent: Monday, March 07, 2016 5:02 AM
To: jkg@xxxxxxxxxxxxxxxxx; 1970hurst@xxxxxxxxx
Cc: crc@xxxxxxxxxxxx; paulholm@xxxxxxxxxxxxx; Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Surprising source of miss in 300 ? In an attempt to keep this in layman's terms, this may help. Electricity will always seek a path to ground. Whether the switch is before the load or after, when the switch is engaged, the path will be completed. The factor that creates the spark is the speed (current) at which the energy will flow to ground. This speed, or amperes, is determined by voltage, and its desire to reach ground. No matter what the amperes (amps) are, there is always a spark. Sometimes microscopic, sometimes catastrophic. If the amps are low, the spark will not become hot enough to burn or melt contacts. Conversely, if the amps are low, the tiny spark will not be hot enough to melt the contacts. This can easily be demonstrated with a D cell battery and a 9 volt battery. Run jumper wires from negative to positive and run those two wire to almost touch the ends together. Notice the resulting spark at the contact point of the two wires. You'll note that the 9 volt jump is a much hotter spark than the 1.5 volt D cell jump's spark. -----Original Message-----
From: John Grady jkg@xxxxxxxxxxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx>
To: Ray Jones <1970hurst@xxxxxxxxx>
Cc: Fern Rivard <crc@xxxxxxxxxxxx>; paul <paulholm@xxxxxxxxxxxxx>; Listsaver 300 Club <Chrysler300@xxxxxxxxxxxxxxx>
Sent: Sun, Mar 6, 2016 11:09 pm
Subject: Re: [Chrysler300] Surprising source of miss in 300 ? I mean 300 door dome light switches never burn up either , and they switch the ground . I think that is what he means. And all along I thought it was melon water and small parabolic mirrors. Smile The reason Toyotas last so long is Toyota drivers . 20 -25 mph . Usually in the left lane , with fogged windows. On the way to 800 $ front brake job. Funny to me , anyway ...
Sent from my iPhone Thanks Fern, but you miss the point. The difference is that the switch is just supplying a ground and there is no potential, or need to do work. Hard to explain, but that's the way my instructors put it,
Think of it as electric welding. Welding is just a dead short that you control, power (voltage) going to ground creating an arc, across a gap, which melts one metal into another to form a bond (weld). That is the maximum definition of potential, being used in a good way.
With power going into a switch, and then on to work and then ground, you create an arc, just as the switch is about to contact the terminal, it jumps across the gap, burning the contacts.
And I can testify that I never replaced any thing with contact points in it on Japanese cars. Not counting the early days of points in Dist. Not being an engineer, that's the way I understand it and practice seems to bear it out. What say you Rich? Yes or no? On Sun, Mar 6, 2016 at 5:30 PM, Fern Rivard <crc@xxxxxxxxxxxx> wrote: Hi Ray: It shouldn’t make any difference as you will be drawing the same amount of current thru the switch whether you are key the positive side or the negative side. The real way to prevent any arcing in the switches would be to have a relay carry the load current. I wouldn’t want to have the 12 volt positive sitting at my headlights waiting for the ground to turn them on. This is just looking for an accident to happen. I’m not a mechanic but have worked on electronics all of my life. Sent: Sunday, March 06, 2016 1:03 PM Subject: Re: [Chrysler300] Surprising source of miss in 300 ? This has nothing to do with the problem, but just some electric lore to digest. You mention arcing in the switches. In Japanese cars (worked on them most of my later career) the switches are switched negatively. We switch positively. So, what happens is "Potential" arcing. Electricity wants to do work, which is why a short is so bad, NO work. Even a little mini light bulb, drawing almost no current is work, so all is fine. So, when we turn a switch, just before the actual contact the current jumps across the space to go to work. This is an arc. Switched negativity, the work is already in the line so you are merely providing a ground to complete the circuit, no arc, work performed. In Japanese cars, testing circuits will drive American techs nuts, until they learn this basic fact. Even the head light bulbs will have the current going thru them, awaiting the switch to provide ground so they can light up (work), If you got this far, go to U-tube and Jay Leno's Garage and look up the Acura NSX video. Awesome car with unbelievable engineering, including separate electric motors for each front wheel and a Armature and field behind the flywheel to provide much more power. On Sun, Mar 6, 2016 at 1:04 PM, paul paulholm@xxxxxxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote: On 03/06/16 13:44, John Grady jkg@xxxxxxxxxxxxxxxxx [Chrysler300] wrote:
> Yes -- they punt you walk . Different kind of problem !!
> Sent from my iPhone
>> On Mar 4, 2016, at 5:13 PM, Michael Moore <mmoore8425@xxxxxxx>
>> wrote:
>> I was about so say I don’t like them because its too hard to
>> trouble shoot a problem based on my experience. But I wonlt say
>> that ! :-)) Mike Moore 300H On Mar 4, 2016, at 1:33 PM, David
>> Schwandt <finsruskw@xxxxxxxxxxxxxxx> wrote:
>> Have you considered going w/a Pertronix?? I did so 20 years ago
>> after distributor problems drove me crazy, some may say I still
>> am!!!
>> -----Original Message----- From: Chrysler300@xxxxxxxxxxxxxxx
>> [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of 'John Grady'
>> jkg@xxxxxxxxxxxxxxxxx [Chrysler300] Sent: Friday, March 04, 2016
>> 1:37 PM To: 'Michael Moore' Cc: Chrysler300@xxxxxxxxxxxxxxx
>> Subject: RE: [Chrysler300] Surprising source of miss in 300 ?
>> Hi Mike, A bad ballast resistor would stop you ---not burn the
>> points.
snip
>> Dwell going UP (if that is correct data) is points way set too
>> close , Mike ...Burning , you would expect an opening up, Dwell
>> drop, unless cam rub block is rubbing down? And so not opening
>> them. Look at the mechanical action with the cap off... There is
>> chance points were set too close, does not matter who did it, did
>> not open enough, they arc across and burn. Or same thing caused by
>> open capacitor. I had mentioned in an earlier email how critical
>> that setting process is ,and hard to get perfect.
>> Sounds like bad cap..They are intermittent too. Adds to the fun.
In the Telephone industry when they used electromechanical switching,
a serious butt load of relays, contact protection was berry berry
important. All most all ganged relays had a form of capacitor/resister
network on them to aid in controlling arcing, Necessary for long
contact material life. Replacing the contacts on wire spring relays was
a daunting task, usually once in use it was a task that was tried to be
avoided. Once that skill was mastered, the technician that could do it
would usually have a long list of switching centers to go replace
contacts, at least in my experience. (got several nice free lunches
doing that project)
YES, usually once contact wear became noticed, the first thing tried
was replacing the capacitor/resister network. ALTHO I can say that
since they were meant to work a long time, they generally were
not defective, ATT built to last the average lifetime of the hardware.
(No 'Made in China' back then)
If I recall rightly, some of the in use relays usually had an unused
contact pair set aside as a backup in case the working contacts burned
out.
--
--
Paul Holmgren
If you could sum up all you felt about life and crystallize
it in one master insight, you would have said it all, and
you would be dead - Fritz Leiber -
-- Ray Jones. Y'all come on down an see us. Ya hear?
--
Ray Jones. Y'all come on down an see us. Ya hear?
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Posted by: "Rich Barber" <c300@xxxxxxx>
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