[Shop-talk] strange automotive electrical problem

Thu May 21 04:55:53 MDT 2026

Check the easy stuff first.  If you suspect the ignition, swap in a new rotor.  Easy cheap and if it doesn't fix it, you can rule that out and move on.
Dave 

    On Wednesday, May 20, 2026 at 07:46:47 PM CDT, Al Fuller <alfuller194 at gmail.com> wrote:   

 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 everythingfrom 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 somethingthat 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 notget 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 PMSubject: Re: [Shop-talk] strange automotive electrical problemJohn, 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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