Help my car is always draining my battery's

[cutty559]

The car is a 1983 Cutlass with a 307 engine. I have no idea what might be happening with my car. Some people told me it might be the wire harness. I have also noticed that when i first start it, it has some sort of a knocking to it. Not real loud, but its there. After a couple of minutes of being on and warming up it goes away and doesnt come back, or atleast until i turn it on like a week later. I've moved the car around from time to time and drove like half a mile and its still very strong. Any advise and/or opinion on the matter is welcome. thanx

 

[DRIVEN]

I'll let the Olds guys give input on your "knock". As for your title question -- Here is the procedure to find battery drain:
1. Make sure that all the accessories are off and the doors are closed.
2. Disconnect the negative battery cable.
3. Put a multimeter in series; one lead on negative post and the other lead on the negative battery cable end. Meter should be set to milliamp (mA) scale. You are looking for a reading of LESS than 500 mA.
If the reading was HIGHER than 500:
1. Remove one fuse at a time from the fuse panel. Start with the radio fuse and the lighting fuse.
2. When your meter drops below 500mA (and it will be a big drop), you have found the offending circuit.
3. Once you have the circuit isolated, determine if there is more than one accessory on that circuit.
4. When the high-draw / shorted accessory is found -- fix it.

The most common places for a battery drain are the radio, glovebox light and trunk light. Also verify that the brake light switch is not sticking.

Good luck.

 

[Doober]

It would also be a good idea to have the alternator checked to see if it isn't drawing current internally. If you can't find the draw with fuses, disconnect the alternator (while the multimeter is still connected) and see what it does. If current drops, check the brown wire going to the alternator and see if it has 12v. If it does, then there may be a short somewhere supplying power to it, because it's only supposed to have voltage present when the key is on.

 

[cutty559]

thanks for the advise. the alternator is brand new so i dont think i might have a problem there, but ill never know till i check it. ill check the fuses first to see what happen. once again, thanks for the help.

 

[Doober]

With the mass production of replacement parts these days, you never know. I've had a few electrical parts (including alternator/ignition module) that were bad from the factory.

 

[rebelgtp]

I have a similar issue happening with my truck right now. About 2 weeks ago I turned on the truck and the stereo BLASTED at full volume even though it was not turned up. I turned it off and back on everything was working fine. A week later my truck had trouble starting, turn the key and click nothin. Give it a second and turn again (sometimes a couple tries) and it would start. Had a free replacement on the battery and swapped it out, everything was working fine. Today I got in turned the key and "click", same thing started happening again.

I don't have a multimeter at the moment (it disappeared with some of my other stuff :evil: ). Anyway I yanked the fuse for the stereo (factory unit) and it is starting up much easier now. Am I right in guessing the stereo is the culprit here?

 

[TURNA]

ALWAYS remember just because it is new does not mean it is good!!!!!


I had a knock at start up and when the car warmed up it was gone.

I had a cracked piston skirt

 

[1evilregal]

does the car sit for periods of time? if so, you may be looking at normal parosidic drain...remember, the computer, if a clock is in the system, and if you have a digital stereo, these will all pull a small drain on the battery, and if it sits for a couple of weeks at a time, the batt will be weak.

if you don't have a ameter, a test light with a regular(non-led) will work... just watch for brightness,when it gets dim after pulling a fuse, you found the circuit to check.HTH

if the car does sit for periods at a time, this may solve the knock... oil draining down from the lifters???

 

[Doober]

Yeah, if it's more of a ticking noise that sounds like it's coming from the top, and not a dull knocking/thudding noise it may just be the lifters bleeding down from sitting. If you don't drive it as often, try running a slightly heavier oil and see if it makes a difference, or put some Lucas in, it sticks to parts better, especially for cars that sit.

 

[cutty559]

ya the car sits for 2-3 weeks at a time and i have only owned the car for like 8 or 9 months. An before i owned it, It sat and only got turnd on like 4-5 times a year for 4 years. it does have a light tick at the top of the engine and after 5 -10 minutes of warming up it completely goes away.