[Shop-talk] strange automotive electrical problem

Wed May 20 02:53:32 MDT 2026

As you know, intermittent electrical problems are some of the most
difficult to track down.

About your only course of action is when it happens, try to monitor/measure
all possible factors before you restart.

Do any of the gauges or indicator lights indicate any problem when it
occurs? Any audible clicks or pops? Does it only happen when it is hot
outside, cold outside, wet outside, etc. Trying to find any common factor
for the moment when the failure occurs could help you start to track it
down.

I know it seems unlikely, but if turning the ignition switch seems to solve
the problem, it could be the ignition switch (I have had two ignition
switches fail intermittently, so I am attentive to that possibility).

You almost have to hope that whatever it is that fails briefly will fail
permanently so that you can track it down.

If it always occurred when you hit a bump (electrical connection) or after
the engine had been running for an hour or so (overheated component), etc.,
you could start to track things down, but it seems totally random.

On Wed, May 20, 2026 at 1:53 AM john niolon <jniolon at att.net> wrote:

> Hey Moose, thanks for the reply.  Harness was done by a pro that does it
> for a living...He is meticulous.  He completely strips everything
> from the car then starts from a blank slate... Everything new.. Nice looms
> and grommets at every hole and hides as much of it as he can.
>
> Every component was new and oem or better... no import crap.   I'm of the
> same opinion as you afa a short to ground but it's gotta be hidden inside
> something
> that we can't see.
>
> Someone on my ford forum suggested putting a volt meter in the circuit and
> watch the voltage for a drop...but you're so busy trying to get out of
> traffic and not
> get plowed it's difficult to remember to watch the meter....   and yes
> this has been going on for over a year...intermittently and even after all
> the changes... it persists
>
> john
>
>
> *----- Original Message -----*
> *From:* <eric at megageek.com>
> *To:* shop-talk <shop-talk at autox.team.net>
> *Cc:* john niolon <jniolon at att.net>
> *Sent:* 05/19/2026 4:40:59 PM
> *Subject:* Re: [Shop-talk] strange automotive electrical problem
> ------------------------------
> John, I would have bet money it was a hidden wire short somewhere. It had
> all the Hallmarks.  But you stated the wiring harness what completely
> replaced. So, that rules that out...
>
> Or does it?
>
> My question, when you said 'headlight to taillight', that is complete.
> BUT was there ANY wire that was in that car that wasn't part of the harness?
>
> Something in dash, neutral switch, tranny indicator, or some other
> component?
>
> I'm still betting on a wire short, but I guess it could be a short inside
> a component.  Maybe inside the alt or other part?
>
> BTW, I'm assuming it was doing this, before you did all these mods, right?
>
> Anyway, that is a stumper.
>
> Moose
>
>
>
> From:        "john niolon" <jniolon at att.net>
> To:        "shop-talk" <shop-talk at autox.team.net>
> Date:        05/19/2026 13:16
> Subject:        [Shop-talk] strange automotive electrical problem
> Sent by:        "Shop-talk" <shop-talk-bounces at autox.team.net>
> ------------------------------
>
>
> Strange automotive electrical problem we need help with…
>
> 55 chevy automatic with 383 stroker motor, carbed, p/s,p/b,a/c
>
> Dakota digital dash system including neutral safety switch and
>
> Transmission gear indicator
>
>
>
> When it is running right, it’s scary strong.  Cruises nicely.
>
>
>
> Problem… when driving the engine dies like you cut it off…BUT will start
> back up
>
> Immediately and run perfectly till the next time it does it.  Might be 15
> minutes…15 days or
>
> three month later. Might do it 4 times in a row or once and not repeat.
> Speed does not effect it.
>
> Engine temp does not effect it…  does it hot or cold. With the a/c on or
> off.  It does not have a
>
> Cutoff switch in the system.  Longest period with no failure is 7 months…
> shortest was 4 minutes.
>
>
>
> When it stalls we checked fuel by looking in the bowl of carb and gas is
> spraying as it should
>
> So we are assuming electrical of some sort.  So far we’ve done the
> following…
>
>
>
> Replaced battery with new red top optima battery and all new battery
> cables (2 gauge I think)
>
> Replaced all ground cables frame/block… frame/chassis with 2/0 welding
> cable with new crimped
>
> connectors and clean, bare metal attachment points
>
> replaced ignition switch (twice… first with import then with oem switch)
>
> replaced coil and distributor with MSD system with spark control box,
> separate coil and distributor…
>
> it was taken from running vehicle.  It's doing the same  thing as the
> original ignition system.
>
> Replaced complete wiring harness…headlight to taillight with new Autowire
> harness…including all
>
> Switches and relays. Professionally done.
>
> Everything else electrical works without a glitch…  we are at the wall
> here…
>
>
>
> Ideas, suggestions, calculated wild a** guesses welcomed…
>
> thanks
>
>
>
> john
>
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