1968 GTO Electrical Issue - Pontiac GTO Forum
User Tag List

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 04-11-2019, 12:56 AM Thread Starter
Join Date: Feb 2016
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
1968 GTO Electrical Issue

Sorry, this may be lengthy to explain, but here it goes. Back in August 2018 I had an MSD 6AL system installed includes distributor, plugs, wires, coil (old style cylinder) and control box. All was working great until around January this year. Noticed the dash lights, and head lights had this glow effect going on (dimming slightly, back to bright and so on) and after market Volt gauge needle was bouncing back and forth. My First thought was Regulator, purchased AC/Delco external Reg and installed. Same issue with lights, but now two other issues show up, (1) at Idle, GEN light comes on and key buzzer tries to buzz with engine running and (2) now getting Engine Run-On (keeps running after key is turned off, and eventually 20-30 seconds later shuts down). So, I had the Alt. checked, it came up as BAD, so I replaced it, same issues. Engine harness had been hacked some before I got the car, so ordered NEW OEM engine harness. Installed new harness, same issues. I had changed out ignition switch last year, so thought maybe it was bad, so re-installed the original switch, same issues. In researching the MSD 6AL I found that the issues are known to happen. To correct the problems, I had to install a Ballast Resister in the system. I installed one and the Engine Run-On was corrected, but still have the original glowing effect and the GEN light/buzzer issue. MSD also includes a Diode that gets installed on port 4 of the Regulator. I put the Diode in and nothing changed. Also thought after market Volt gauge was bad, so installed all new gauges (oil, water, volt), no change. Last resort was getting another 6AL control box in case mine was faulty. Installed new box and same issues. I am at a total loss now with why the glowing effect and GEN light wants to come on. At Idle the GEN/buzzer comes on and with added RPM the glowing effect and Volt gauge bouncing happens. What could possibly be doing this? I practically have a whole new electrical system now. Thanks for any help you can provide.
Bill68GTO is offline  
Sponsored Links
post #2 of 3 (permalink) Old 04-14-2019, 02:25 PM
integrity6987's Avatar
Join Date: May 2017
Location: NW Ohio
Posts: 127
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
FWIW - I had these symptoms last year at this time.
Turned out to be a short under the dash (courtesy light)



"Pray as though everything depended on God. Work as though everything depended on you." - Saint Augustine
integrity6987 is offline  
post #3 of 3 (permalink) Old 04-15-2019, 10:09 PM Thread Starter
Join Date: Feb 2016
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
PROBLEM SOLVED: The externally regulated alternator was not producing enough amperage to the system. Installed a 100 amp internally regulated alternator, jumped the external regulator wires (F-to-3, 2-to-4) and all is working with 14 volts flowing and no issues at all.
Bill68GTO is offline  
Sponsored Links

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring

Quick Reply

Register Now

In order to be able to post messages on the Pontiac GTO Forum 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 for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
No Crank / electrical issue 72 GTO 11th Indian 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 4 06-23-2018 09:36 PM
Electrical Issue in Dash/ Won't Start 66 GTO Indecision 1964-1974 Tempest, Lemans & GTO Convertible Top, Interior, Glass and Trunk 5 09-19-2014 10:39 PM
69 GTO Electrical Issue 69PMDGTO 1964-1974 Tempest, LeMans & GTO Projects, Barn Finds & Restoration Discussions 4 02-07-2012 03:41 PM
Need Help, Odd Electrical Issue After HID install fleshmcfilth123 2004-2006 GTO General Discussion 4 06-14-2010 01:45 PM
starter or electrical issue zomowiec Service, Maintenance and Technical Discussion 2 04-11-2008 11:26 AM

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