66 Caprice: Battery drainage - Impala Tech
Electrical & Wiring Troubleshooting electrical problems

LinkBack Thread Tools
post #1 of 7 (permalink) Old 04-25-2014, 06:03 PM Thread Starter
Join Date: Apr 2014
Location: North Carolina
Posts: 19
66 Caprice: Battery drainage

I have an issue where my battery is being drained. I have replaced the alternator, the voltage regulator, battery. I can not determine what's killing my battery. Any ideas?
S.L.A.M.M. is offline  
Sponsored Links
post #2 of 7 (permalink) Old 04-25-2014, 06:35 PM
Join Date: Jan 2006
Posts: 12,362
Welcome to the Team!

You have a short somewhere in your wiring. You cam measure the amount (in amps) at the battery with a meter which will allow you to calculate how long it will take to drain the battery flat knowing the Amp/hour rating of the battery. Something is completing a circuit somewhere in the car. It could be due to corrosion or burnt points on a contact in some switch that is allowing current to flow when it shouldn't be.

Your options are a battery disconnect switch or to replace the wiring and switches (the easy way out). Or you can attempt to trace the source of the short by starting at the ignition switch (by measuring the Ohms the switch offers to Voltage), then pulling all of the fuses one by one to isolate the bad electrical circuit. Once you know the circuit with the short you pull every inch of wire looking for a bare wire or evidence of corrosion (a green trace of copper oxide) at a point of termination that could be bleeding off power.

Big Dave
Big Dave is online now  
post #3 of 7 (permalink) Old 04-26-2014, 06:59 AM
Senior Member
Join Date: May 2006
Posts: 1,055
Blog Entries: 1

Also check for simple drains, maybe a bad adjustment on the interior door jam light switch not allowing interior lights to go off, check same and harder to find if you have a trunk light, same for a hood light if you have one. Check also console lights if applicable and glove box light.



1966 Impala SS

Please Visit our new site:
1959 through 1988* window stickers, car shippers, dealer invoices, retail sales orders and tank stickers, expertly reproduced, for most Chevrolet Models.

fsc66 is offline  
post #4 of 7 (permalink) Old 04-26-2014, 09:05 AM
Join Date: Jan 2007
Location: Lewisburg, Ohio
Posts: 2,909
Aftermarket radio's are bad for that also.
dadstoy is offline  
post #5 of 7 (permalink) Old 04-26-2014, 10:04 AM Thread Starter
Join Date: Apr 2014
Location: North Carolina
Posts: 19
Thanks Big Dave! I believe I will start with the ignition switch. I initially swapped it out with a 65 impala switch. I also had to rewire it as well. Do you have a pic or 'color coded' diagram of the ignition switch wiring? I'm pretty sure I got it wired correctlly but I am sceptical of the gauge of the wiring I used.
S.L.A.M.M. is offline  
post #6 of 7 (permalink) Old 04-26-2014, 10:11 AM Thread Starter
Join Date: Apr 2014
Location: North Carolina
Posts: 19
Paul, I did replace my rear lamp harness. Everything appears to be connected. The console, hood, trunk and glove box lamps are all disconnected right now.
Thanks for the suggestions.
S.L.A.M.M. is offline  
post #7 of 7 (permalink) Old 04-26-2014, 10:38 PM
Senior Member
Join Date: Apr 2013
Location: Canada
Posts: 324
With the positive cable removed, put a test light between the cable and the positive battery post. See if it lights up. If so-

Remove fuses one at a time as suggested to see if the draw goes away.

If not, then try unplugging the connector on the back of the ignition switch. Maybe somehow you got something wired up wrong on that connector?
Darth is offline  
Sponsored Links

alternator, battery, drain, voltage regulator

Quick Reply

Register Now

In order to be able to post messages on the Impala 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 for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

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