Continued electrical problems

[Topless69GT 28]

I posted a while back about my car not starting when it is warm. It seemed to get better and did not cause any issues for several weeks. But now it is doing it again and is now cutting off while I am going down the road. It is like the key was shut off. I replaced the ignition switch and it is still doing it. I think I am going to put a new ignition wiring pigtail since that and the coil are the only things I have not replaced. I actually have a ignition pigtail from another car but it is for a factory tach car and I have a converted wiring harness for a tach. The current converted harness in the car does not have the pink resistor wire but the pigtail I have does. Can I just use the pigtail and not hook up the pink wire? It appears to be the same in everyway but has the pink wire.

 

 

[Midlife 814]

Yup...just don't hook up the pink resistor wire pigtail.

 

I doubt your problem is the ignition switch itself; most heat-related issues are coil or distributor related.

[1969_Mach1 333]

I also wonder if something is wrong in the ignition system like Midlife suggests.  What kind of ignition system does the car have?  Does your car have a factory tach?  If so, has it been retrofitted, or is it still an original current triggered tach and connected in series between the ignition switch and the positive side of the coil?  If it still an original non-converted factory tach it needs to have the resistor wire in the circuit between the tach and positive side of the coil.  Otherwise the tach will eventually fail.  Also, if the factory tach fails the car will often not run then its time to by-pass the tach and have it retrofitted with movements of todays technology.  Plus the retrofit tach will work with any type of ignition system

 

Intermittent problems are sometimes hard to diagnose.  Ideally, you'd like to check for spark at a spark plug and at the coil when it won't run.  But, I've had cars with intermittent issues and as soon as you start checking something it starts back up and runs fine.  Then you have to start making educated guesses and start changing parts.  It can get frustrating. 

[danno 128]

I had a similar problem.  Turned out to be an bad coil.  I say replace the coil first, they are cheap and easy to replace.

[Topless69GT 28]

Looking at the old ignition plug I noticed when I  unplugged it that the plastic plug around the yellow wire is melted. Now the question is why did that happen?

[Midlife 814]

A melted plastic plug occurs when the wire gets too hot due to excessive current and/or resistance.  This can be due to a poor connection, corrosion, or a short.  A short typically melts the wire insulation; the excessive resistance results in a discolored wire. 

 

Hope this helps.

[Topless69GT 28]

_{I am wondering if it is time for me to put in my spare underdash harness. I have been chasing electrical issues for quite sometime.}