Electrical Drain - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old Jun 12th, 03, 07:35 PM Thread Starter
Join Date: Jun 2003
Posts: 17

I just recently bought a 67 Camaro RS and found that it has an electrical drain problem. When I bought the car, I test drove it, negotiated the price, and when I went to start the car again, the battery was dead. Since then, the car has drained the battery twice. After another dead battery, I suspected it was an old battery so I bought a new optima battery. After letting the car sit for two weeks, I come back to an dead battery. The previous owner mentioned replacing the wiring harness in the car which he said had cured all his electrical problems. Therefore, I assume the wiring harness is not the problem. Is there a way to check for a bad wiring harness or a bad installation that could lead to an electrical drain? If the wiring harness might not be the problem, are there any ideas as to what might cause such a drain? Are there any components that are notorious for draining the battery? What strategies should I use to determine the cause of the drain? Basically, I want this electrical drain problem fixed so I can drive the car daily without the fear of having to jump start my car all the time. Thanks in advance for all the help.
67 Camaro RS is offline  
Sponsored Links
post #2 of 6 (permalink) Old Jun 13th, 03, 05:13 AM
Senior Tech
Join Date: Jan 1999
Location: Quebec Canada
Posts: 142

One strategy which has worked for me in the past
is to check for current flow with everything off. If you have a clock disconnect it. There should be no current flow at this point, however as will be in your case, there will be some flow. Pull one fuse at a time and recheck for current. This will isolate the circuit that is shorting. You can then probe the problem circuit to trace the short. Because there are so many points where this short could occur, once you have a strategy stick to it otherwise you may have problems finding the problem circuit.
Jim McGregor is offline  
post #3 of 6 (permalink) Old Jun 13th, 03, 08:39 AM
Senior Tech
Join Date: Mar 2002
Location: Austin, TX, USA
Posts: 5,277

To check for current flow, use a test light between the battery post and cable (doesn't matter which). I'd recommend not using an amp meter since the electrical system is capable of delivering hundreds of amps. Many DVMs have been fried working on car electrical systems.


68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI
dnult is offline  
post #4 of 6 (permalink) Old Jun 25th, 03, 10:54 PM Thread Starter
Join Date: Jun 2003
Posts: 17

This weekend I tried connecting a test light between the battery and the cable. The light did not go out after all fuses were pulled - it remained dimly lit. An ammeter revieled an electrical drain of 0.150 amps with the radio fuse removed (around 0.350-0.400 with the radio fuse in place). The car still drains the battery. Now I am lost on what to do next. I suspect the alternator is bad, but it still charges the battery at 14 volts. Could it be the voltage regulator has gone bad? I also noticed that there are only two wires going to the alternator, both are terminated with one connector attached at the back of the alternator. Is this a one wire alternator? The alternator gives full voltage to the battery whenever the engine is running. I verified this with a Vat40. When the car is shut off, the battery is at something around 12.75 volts - give or take 0.10 volts. Shouldn't the battery be around 14 volts immediately after the car is shut down? Also, if I wanted to replace the alternatror back to the 3-wire style, what would be involved. The previous owner of the car replaced the wiring harness and I haven't looked if there are more wires for the alternator or not. I hope someone can tell me what to look for in trying to find the electical drain as well as possibly converting the alternator back to a 3-wire setup. Sorry for the long post and thanks for all the great advice.
67 Camaro RS is offline  
post #5 of 6 (permalink) Old Jun 25th, 03, 11:38 PM
Senior Tech
Join Date: Feb 2002
Location: seattle,wash
Posts: 142

How about hooking up a battery disconnect, the one that connects to the battery post.I know it's not fixing the problem, more or less going around it; but it enables you to keep driving the car without worrying about the battery draining.I use 1-wire alternators on both my cars.At times one car might sit for a couple months,but they'll still fire up.I read an article, I think in my Powermaster catalog, that 1-wire alts. draw a certain amount of current when the car is off. The current draw is very small; but if whatever draws that current is somehow shorted to the alts. case, you'd have a complete circuit.I know it's not much ,but it an idea.
kool is offline  
post #6 of 6 (permalink) Old Jun 26th, 03, 03:11 AM
Senior Tech
Join Date: Sep 2001
Location: Temple City, Ca
Posts: 523

Disconnect the alternator wires and repeat your tests. May be a leaking diode in the alternator.
John_Muha 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