mcmac73

Battery goes dead if car is left sitting for a few days, have tried changing the battery( 3 times). We then tried unhooking terminal from alt. SUCCESS! battery would stay charged forever, so we changed alt. 1 week later, dead again, I mean FLAT.Anybody with any ideas??? :confused: :confused: I have put a meter on the car to measure loss and it reads .3 a with alt hooked up, 0 with alt disconnected. I have been told .3 amps shouldn't really be a problem.

my74ls4

Put your meter between ground and the negative post and start pulling fuses. If the short is in the fuse panel you will find it. If not looking for it gets a little more interesting. I did the above and did not find the short. I found it after I disconnected the harness going to the starter. There is a ground that is in the same harness as the starter and it was on the hot post. Once I put it to ground the short went away and the fan for the heater started working. Good luck.

Super Stock

In the meantime put a quick disconnect on the neg. side if you want to.

REDRED62

To start with, charge the battery.

After the battery is charged, take a volt reading on the battery with it disconnected.

Attach the battery post to the battery. Take a volt reading from the battery post.

Subtract the difference from the two readings will establish a draw factor. Leave the battery cables on the battery.

Go to the fuse panel as mentioned above. Pull the fuse’s from the panel one at a time. After you take one fuse out, go to the battery and take a reading again. If the volt reading is the same as the stand alone reading, you have isolated the draw circuit. If the reading is less but not equal to the difference in the stand alone reading leave the fuse out and pull another one. What you are looking for is a current draw elimination that match’s the difference between the battery stand alone reading and the battery installed reading. (Current draw)

Make sense??? I hope, it’s late and I”m tired.

Once you isolate the circuit the draw is on you can proceed to check all items and grounds attached to that circuit.

Back feeds are a common problem. Grounds not attached where they below, will cause a circuit to hunt for a ground. This may also cause another circuit to draw.

mcmac73

thanks guys,guess there is no easy fix, I'll try pullin fuses as instructed.STW :cheers:

stpman

I think he found his draw by what he said in his first post
"if I disconnect at the ALT. is stays charged forever"

If there is a diode shorted in the alt it WILL drain the battery over time.
Get your Alt. checked to rule it out.

Steve :steering:

Corvette ED

The first fuse I would pull is for the interior lights. See if the battery goes dead with this one out.

mcmac73

Yea, so I changed the alt. :confused: Goin back to pullin fuses, first stop, interior lights :cheers:

DP77Vette

Check the door jam interior light switches. That was my problem!!!

mcmac73

Ok, charged the battery(new), put a meter on it, draw .3 amps, pull brown wire on alternator, no draw, changed alt., same problem, started pulling fuses one at a time, no change in draw. the starter ground was mentioned in a previous post, mine doesn't appear to have one????????????? :confused:

Steve Grodin

Check to make sure the light in the center compartment behind the seat goes off when the compartment top is closed.

ettev

Are you absolutely sure your battery is good. Take it to a garage and have it load tested. It may only be holding a surface charge. It doesn't matter how old it is, I just had one bad right off the sales shelf!

AGVI

How would you test to see if it's the door jamb switch? :confused:

mcmac73

this is the third battery, if it was the door light switch or the rear compartment light, wouldn't I lose the draw when i pulled the fuse???? :beatdeadhorse:

l2vette

Do you have a after market stereo?? They usually requre a power source to keep the memory and clock set. Try disconnecting that.
:cheers:

mcmac73

Yes I do have an after market stereo, but if I pull the fuse the draw should change, right??????????????????????