DeTomaso Mailing List: November 2000, Message #21

Interesting experiments....FYI: The "kill" switch (probably Merit or Autolec)is installed on race cars for one(maybe two) purpose's only: To cut power to electric fuel pumps and/or eliminate a possibility of spark(both fire related) 
Cars without fuel will discontinue running(and hopefully, burning)  

-----Original Message-----
From: Charles F Engles Jr. [mailto:engles@qns.com]
Sent: Tuesday, October 31, 2000 8:42 PM
To: Multiple recipients of list
Subject: Re: What I learned in school today...:<(


Dear Mike,

        Let me console you.  In my experience, if you drive your "club car"
these things will happen.  You just have to look upon it as an opportunity
to meet new people, learn new things about your car, develop the
conversational skills of tow truck drivers  and eliminate those marginally
weak parts and systems that need upgrading.  Why, I've had to rebuild an
engine or two myself.  :-)

                "The engine was running perfectly until it stopped running",
Chuck Engles


----- Original Message -----
From: <MikeLDrew@aol.com>
To: Multiple recipients of list <detomaso@realbig.com>
Sent: Tuesday, October 31, 2000 6:10 PM
Subject: What I learned in school today...:<(


> Hi guys,
>
> In keeping with my whole "drive your club car" philosophy, today I elected
to
> take the Cobra to Travis AFB where I had a number of errands to run.
>
> It was a beautiful day up here--the leaves are turning, the air is crisp,
the
> skies are clear--great Cobra weather.
>
> As I pulled into a parking space, I was suddenly struck with a
thought--years
> ago I'd had a super-duper electrical engineer guy install a key-style
battery
> cut-off switch.  I'd demonstrated repeatedly that the car will NOT start
when
> the switch is in the "off" position (i.e., sitting back in the house!),
but
> I'd never checked to see if turning the switch off with the engine running
> would kill the engine.
>
> The answer is, why no, it won't.  I sat there for 5 or 10 seconds or so
with
> the cut-off switch key in my hand, then shut off the ignition at which
point
> the car promptly quit, as you'd expect.
>
> When I came back out a half-hour later, with both keys energized the car
> started right up.  I pulled into the street, drove 100 feet and was
instantly
> enveloped in electrical smoke pouring out from under the dash. :<( :<( :<(
>
> I managed to shut off both keys (one with each hand) and steer to the side
of
> the road (third hand?) to assess the situation.
>
> The smoke was still thick, but diminishing when I hopped out and peered
under
> the dash, and I saw the source of the smoke was my MSD tach adapter.
> Apparently, when the alternator is producing 1.21 gigawatts of energy and
you
> remove the path to the battery, that power takes the path of least
> resistance, which in this case appears to have been DIRECTLY to the tach
> adapter. :<(
>
> Not having any wiring diagram for the ignition circuit, I began just
tracing
> the wires with my fingers.  Two of them went from the tach adapter into
the
> MSD box, while the third went to the ignition switch.  A-ha!  That must be
> the power source.  Remove that, and perhaps things would be okay?
>
> Well, yes, except that the car now wouldn't fire at all.
>
> At this point, I'd gathered a small crowd of helpers, strangers all.  One
> older fellow in a mint, beautiful '67 Mustang GT fastback which is his
daily
> driver (drive your club cars!) was especially helpful.  Ford guys stick
> together!
>
> Hopefully, I attempted to start the car with everything connected, hoping
> that the smoke was just a fluke.  Nope--more smoke came out, and of course
> the tach no longer worked.
>
> (A side note--As Shane first revealed, most people don't know that the
single
> root source of power in electrical applications is SMOKE.  You can take
all
> your EE degrees and pile them to the rafters, but I'm here to tell ya, the
> minute you remove the smoke from ANY electrical component, that component
no
> longer works.  Ergo, the component is powered by smoke!)
>
> Another peek revealed that the single wire from the ignition switch had
been
> butchered and turned into two wires, one of which went to the MSD box
itself.
>  So now I was faced with a dilemma--do I cut the short wire leading to the
> tach adapter and hope for the best?  Will the car run?
>
> It felt a little like those movies where James Bond has to cut one wire to
> prevent the nuclear bomb from detonating, but if he cuts the wrong wire,
> BOOM!  But then I figured that my options were either (1) cut the wire,
the
> car doesn't run and you go home on a tow truck, or (2) don't cut the wire,
> the car continues to burn merrily, and (if you're lucky) you go home on a
tow
> truck.  So what did I have to lose?
>
> As fate would have it, cutting the wire had the desired result.  The tach
> adapter is now unpowered (not that it worked anymore anyway) and the car
runs
> fine.  A quick call to Summit has a new one on the way for $51.
>
> Now I need to figure out why my kill switch, doesn't.  And in the
meantime, I
> won't be shutting off the kill switch with the engine still running
anytime
> soon!
>
> Mike