Battery Keeps Dying

[scout30501]

I have recently purchased a 1986 Corvette. I put a new battery in it about 3 weeks ago and it is already dead. The factory radio was replaced before I bought it. It has about a 3/8" red cable that comes from an amp in the back hooked directly onto the positive battery terminal. Could that be the problem? Suggestions?

 

[vetteoz]

I put a new battery in it about 3 weeks ago and it is already dead. The factory radio was replaced before I bought it.
Suggestions?

Many well documented battery drains with age on these cars.
For example , the limit switches in the headlamp motors worn so the motors continue to draw power all the time , the power seat switches not working so the motors draw power

Only way to identify is by a process of elimination
You disconnect the batt cable and put a DVM between it and the batt post and measure the current draw
Then pull the fuses one by one to see if anything changes.
If nothing identified there then there are other power feeds that come direct from the battery ( from the starter terminal on your year I believe ) that need the same tests.

I would disconnect any obvious non stock wiring ( like the amp ) before testing

 

[Antz81]

It has about a 3/8" red cable that comes from an amp in the back hooked directly onto the positive battery terminal. Could that be the problem? Suggestions?

Normally an amp will have a separate control wire coming from the radio to turn the amp on and off so they don't drain your battery. But if its been wired wrong or there is a fault somewhere the amp could cause your battery to drain.
Following previous suggestions will help you find the problem.

 

[scout30501]

Thanks guys for the help.

Many well documented battery drains with age on these cars.
For example , the limit switches in the headlamp motors worn so the motors continue to draw power all the time , the power seat switches not working so the motors draw power

Only way to identify is by a process of elimination
You disconnect the batt cable and put a DVM between it and the batt post and measure the current draw
Then pull the fuses one by one to see if anything changes.
If nothing identified there then there are other power feeds that come direct from the battery ( from the starter terminal on your year I believe ) that need the same tests.

I would disconnect any obvious non stock wiring ( like the amp ) before testing

I am taking it to an my audio guy on Sat to get him to check how the audio equip is wired in and then go from there. I also am having the timing reset because the car is sometimes hard to start and seems to be running really rich. So I may be draining the bat while trying to start it. If this does not work, then, I will get a DVM and go from there. Thanks for all the help!

 

[vetteoz]

I also am having the timing reset because the car is sometimes hard to start and seems to be running really rich.

Before wasting time and $$$ , pull the computer error codes to see if anything showing
See
C4 Corvette Diagnostic Code Recovery Techniques

This is the 1st course of action with these cars should you have any engine problems; it tells you if any of the sensor or input circuits used by the ECM to control the engine are faulty

A rich cond for example can be caused by a faulty CTS ( the sensor that gives engine temp to the ECM ) showing that the engine is always cold so the ECM makes it rich all the time

 

[fatbloke-dim]

Headlamp limit switch ?

Hi, VetteOz,

seen your reference to limit switches in the headlamp motors . I'd guessed there must be something of that nature in there , but until now had seen no mention of 'em . Are these switches something that can be fixed or adjusted? Or would rebuilt motors be a way to fix it ? I have the problem of a .25 Amp drain to the left motor , which drains the batt in about 2 weeks ,I guess working from it's A/H rating . As a definite indicator of the problem being here , the motor armature jumps to attention when connecting the batt or replacing the main lighting fuse , if that has been pulled . Are there any home-brew fixes possible here ? Don't want just pull it and mess with it if not as the car is regretably up for sale due to my missus's spinal disability , and has been advertised already , but I don't like the notion of the car not being 100% when sold . Cripes ,I might even need to get a M*57*4ng !