Battery Drain on 82

[Rookie Vette owner]

I believe this is an old problem as I have seen threads about shorts, battery drains, etc.. The question I have is: what would be a nominal or acceptable current reading with the ignition turned off? I have found one drain in the courtesy light circuit (and lights that don't work) so I have pulled that fuse for further investigation. I am now showing a pull of about 90 milliamps (I figure some of this is for the clock and computer). Thanks, Tom :confused

 

[Rodney Gold]

Lets say you have a 55amp hour batt - 100 milliamps = 1 amp for every 10 hrs , so basically it draws 2 amps a day , so in "theory" the bat charge should last for at least 20 days...?
If I dont use my vette for a week or 2 , the bat runs down .. 20 days ..NOT
Instead of futzing around looking for reasons , I installed a battery cut off switch in the batt compartment. Nowday , I just twist the switch and Boom..it starts like a champ. Good anti theft device too.

 

[Rookie Vette owner]

It's just seems a little excessive to me. My 73 can set for a month or more and never miss a lick when I crank it. The car has a history of this problem as she came with a "Battery Brain" set up to cut off if the voltage drops below 11.9 V. As far as the regular "disconnects", it seems like a bit of an inconvience to have to always remember to turn it off when you get out even though I guess it seems like a wise choice when it comes to vette's pyromaniac personalities. Thanks again! Tom

 

[vetteboy86]

The easiest way I have found to find battery drains, is to connect the amp meter. Now note the current. Pull one fuse at a time, and check the amp meter. If no change, then replace the pulled fuse, and pull another one. Eventually you are going to pull a fuse and see the battery drain change. Now if you pull all fuses and no change in battery drain occurs, you have some source that is not fused at the panel. That may be easy to find, just look for some spiced wire that looks non factory.

 

[Rookie Vette owner]

The easiest way I have found to find battery drains, is to connect the amp meter. Now note the current. Pull one fuse at a time, and check the amp meter. If no change, then replace the pulled fuse, and pull another one. Eventually you are going to pull a fuse and see the battery drain change. Now if you pull all fuses and no change in battery drain occurs, you have some source that is not fused at the panel. That may be easy to find, just look for some spiced wire that looks non factory.

Thanks that's the way I found the drain on the courtesy light circuit. Pulling the rest of the fuses failed to drop the drain below the 90 mils. I'm hoping to verify the nominal or standard system drain and hoping that it is close to the 90 mils I have. One other thing, I must be getting old, because I don't remember the fuse panels being so hard to get at about 20 years ago!

 

[Rodney Gold]

I only use the cut off when i park the car in my garage and I know i might not use it for a week or so , dont use it as a general anti theft when i go out with the car - got a decent alarm immobiliser for that.

 

[Rookie Vette owner]

Just an update, I found the reason for the power drain on the courtesy light circuit, it was the delay timer as documented in a lot of other threads on the subject. I made a jumper to plug into the connector till I can find a replacement component for the timer circuit. Still tracing the other 90mill drain, and hoping that is just normal for the system.