Topic: ignition not turning off when hot

[kc79ta]

By 2 pin plug you mean the red and brown wires? The red should be hot all the time as it comes (in around about way) from the battery. The brown would only have voltage when running.

It would almost sound like your getting a short between that red wire and your ignition wire (pink).

[medicman]

Ok, so this what I did. I checked the pink wire off the distributor and it has power with the key on and then off when the key is shut off.

Now when the car is running the alt. plug has power to both sides,  and both sides when the key is turned off. There is a major rough idle when the key is shut off due to pink wire at the distributor not have power fed to it.

Where should I even start looking for a short?? This is a new engine harness from classic ind.

[medicman]

I think my alt. is staying energized somehow and keeps slightly feeding the engine somehow. Even though the pink wire is dead when the ignition is off, does this make any sense??

[pancho400cid]

Wow.... that sounds pretty weird... and frustrating.  Reminds me of a whacky problem a firend and I chased for months on his 69 Mach 1.... LLOOOooonnnggg story short.... add-on tach had a wire shorting where it passed thru firewall.

Suggestions:

1 - get a factory wiring diagram and verify your new harnes by "point-to-point" wire check.  Maybe they goofed up at the mnfr?

2 - disconnect your pink wire at both ends and run a jumper from point a to b... then you know it isn't being cross fed from elsewhere... mind you I'm not looking at a wiring diagram... so may not be doable...

Good luck!

[kc79ta]

Not really. With no power at the pink wire your ignition should be dead ( no spark ). Did you ever check with a timing light?

You had said it was at to body shop for over a year. You did put freash gas in the car when you got it back. Old gas will make the engine diesel.

Just another thought : When you check for 12v at the pink wire with the key on does the meter say +12v or -12v?  Running the balck meter lead to ground and the red to the pink wire.

[kc79ta]

pancho400cid made a good point. Plus make sure the brown wire from the aternator is NOT the brown wire that goes to the distibutor.

[ta78w72]

He could simply disconnect the batt terminal on the distributor when it's running on.

[medicman]

I FOUND THE PROBLEM!!!!  Ok are you ready for this?? The alt. has a excited energized regulator in it. The alt I have does not want the 2 pin plugged in, If you do plug it in it will give you the symptoms that I have been experiencing.

Only reason I found this out is that a old fella who used to rebuild alts told me that some classic cars convert to the excited regulators to make the engine bay less messy of wires.

If I leave the alt unplugged it starts fine and shuts off fine. So I was on the right track but I never knew about excited energized regulators, WOW did I learn the hard way.

Going to change that damn regulator $15.00 bucks and all my headaches are gone.

Thanks for all the help fellas, hope to return the favor someday.

Elliott

I don't understand why this only started with symptoms after the body shop!!

[pancho400cid]

Congrats!

Amazing!.... Never heard of such.... yet another thing I need to remember, but probably won't.  I really learn a lot poking around on this site.

IMO you still need to be sure the alternator is charging properly with the thingy un-plugged (assuming you haven't already).  If you trust the volt meter on the dash, that's one way.

Better is a volt meter (set to DC volts) from pos to neg on the battery terminals.  Should read like 11.5 to 12.5 VDC with car off, and about 13.5 to 15 VDC running (am I stating the obvious again?  sorry...).

[kc79ta]

Wow. never heard of that one before. Let us know after you change it that all is good.

[medicman]

Thats the great thing about this site, you can bounce ideas around and find the problem. I called my buddy who has been a gm mechanic for over 25 yrs and he had no idea. This is a new one for all of us.

I will give a post when I get it on the car with the "normal" regulator in it and let everyone know how it works.

Cheers from Canada,
Elliott

[medicman]

http://www.alternatorparts.com/what_is_a_self_exciting_alternator.htm

Follow this site and it will explain what kind of alt I have. 

Cheers

[medicman]

There is also a simple way to fix the back feed from the alt. I could of just used a anti feed connector. It simply plugs in the alt and goes to the original wiring. It costs about 4 bucks and saves you the time of taking alt apart.

Cheers.

[Amtrak]

you had the ignition switch wired wrong  the hot to the alt and hot to the ignition are on two seperate poles on the ignition switch to keep the car from doing what yours was doing

[medicman]

Thanks for the suggestion and I could see how it would cause the same issue if I had  it was wired wrong, but not in this case.

It was not wired wrong. I tested every single wire multiple times.

To make sure it was not a short or someone else prior to me owing the car and playing with the sires I installed all new wiring and a new ignition switch. 

The whole problem was a back feed out of the alt.

The car starts and shuts off fine now. If it was a wiring problem, changing the voltage reg would of not solved my issue.

Cheers.