beast won't die - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old Jun 15th, 04, 03:45 PM Thread Starter
Tech Team
Join Date: Mar 2004
Location: illinois usa
Posts: 60

Finally have my 68 running ,one small problem the motor keeps running even when key is shut off.Running a Powermaster alt. w/ either 1 or 3 wire hook-up. Am using 3 wire w/ adapter for int. reg. also MSD 6al,dist.& coil. Have red wire from box connected to white wire from ignition using mini starter so yellow wire not used.When I turn key off gen. lite stays lit nothing smells hot all wires seem fine. Any ideas?
racermike is offline  
Sponsored Links
post #2 of 5 (permalink) Old Jun 15th, 04, 04:42 PM
Senior Tech
Join Date: May 2004
Location: kansas city, mo
Posts: 768

usually if there is nothing wired incorrectly a car that runs on will have one of/or two things wrong.

one, the idle is set too high and the throttle valve in the carb isn't shutting all the way when you turn it off.

two, timing is too advanced and you are getting some self detonation. the higher the compression of your motor the more this may occur.

check those for sure. then check to make sure the ignition wire to your distributor is hot only when the key is in run and start positions.

i'm not familiar with msd products but enough guys here are. i'm sure they can help you better than me. but do check your idle speed and your timing.

might also mention if it is "dieseling" or actually running smoothly and capable of high rpms as if the key was on and you were driving.

good luck, it'll stop when it runs out of gas i'm sure.

1969 SS X55 NOR added RS all NOS sheetmetal, ground up resto. 24 year project and dream. optioned out the wazoo. in one thousand pieces, and coming together finally.
Run269 is offline  
post #3 of 5 (permalink) Old Jun 16th, 04, 01:43 AM
Super Moderator
Bess-68's rule
Everett#2390's Avatar
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,927
Thumbs up

The alternator is backfeeding the electrical system. Using an internal alt with alt in 3-wire configuration, the voltage sense wire should be on its own ign/acc terminal separate from the ignition contacts on the ignition switch.

As long as the sense wire has voltage supplied onto it, the alt is live. When the voltage is taken away, alt dies, engine quits.

Or somewhere along the wiring, you've wired the two circuits together. My bet is the alternator is still supplying volts.

Many 70's vehicles came with a two separate IGN terminals, one for ignition and the other for the alternator.
Everett#2390 is offline  
post #4 of 5 (permalink) Old Jun 17th, 04, 06:08 AM
Senior Tech
Join Date: Sep 2002
Location: Wilmington, DE USA
Posts: 166

Take a look at this... It should solve your problem. I had the exact same issue and these steps worked for me.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

L48 350, BTO 2004R Level 3, 12 Bolt 4.10
New Project:
1969 Shelby GT350 (pics soon)
rcatalano is offline  
post #5 of 5 (permalink) Old Jun 19th, 04, 07:08 PM
Gold Lifetime Member
prostreet69camaro's Avatar
Join Date: Jul 2003
Location: Spring Texas
Posts: 5,580

I added the diode and it worked fine. Mine did the same thing yours did. If I disconnected the 2 wire plug on the alternator, then the motor would turn off with the ignition switch. Just make sure you install the diode in the right direction. It supplies voltage to the alternator and the diode blocks the voltage going back.

69 Camaro Prostreet - purple w/ghost flames , 502 w/ 871 blower

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
prostreet69camaro is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome