[Shop-talk] strange automotive electrical problem

john niolon jniolon at att.net
Wed May 20 20:40:45 MDT 2026


yes  Al...  it shuts down like you turned off the ignition... now a starving 
type dying
 
as for moving the shift lever to neutral... that is the first thing done to 
keep momentum to get it off the road...  As far as going into park... it has 
never failed while sitting still or parked, 
it's always when moving.
 
Jim... this is a custom street rod and other than maybe the spark control box not sensing enough voltage there are no other sensors.
 
Jeff,  both us and the wiring guru have tried to check every connection that might be suspect and found nothing, but we're 
not ruling out a pin slipping back inside a connector like David suggested...
I've had that happen in my truck... it was the devil to find.   something to check...
 
Thanks all for the advice and suggestions guys...   I wish the dang thing would just fail completely and stay that way... maybe even make some smoke (just a little)  At least we'd 
have a failure point instead of
a gremlin like this.

 

----- Original Message -----
From: Al Fuller <alfuller194 at gmail.com>
To: john niolon <jniolon at att.net>
Cc: <eric at megageek.com>, shop-talk <shop-talk at autox.team.net>
Sent: 05/20/2026 7:39:57 PM
Subject: Re: [Shop-talk] strange automotive electrical problem



It sounds like you are/have ruled out fuel starvation, indicating it has fuel 
as far as the carburetor (and presumably the cylinders), and you appear to be 
describing a sudden 'cut off' as opposed to the less sudden dieing out do to 
temporary lack of fuel. Yes?


If so, it seems like it would need to be a fault in the ignition system that 
allows spark, then changes state to deny spark, then returns to the prior or 
similar state where spark gets called for, produced and delivered.


________________
Sent from my phone 
Best Regards,
Al Fuller


On Tue, May 19, 2026, 10:52 PM 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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