mrmint69

Please move to the proper area if this is not in the right section. I replaced the battery and alternator. I was having a problem for two years when it would sit over the winter only getting started every two weeks of longer having a dead battery. I want to see if it was either of these items that caused it. I tested the battery yesterday and the volt with the car off was 12.44. Will the battery loose low amount of voltage normally and what would show I still have a problem? Someone said a bad alternator can cause it to drain over time at the auto parts store. Also should I only check it with the car off before starting?

my1994z28

My buddys car is doing the same thing,the clock on the radio was staying lite up and killing the battery..He did not want to believe me until I pulled the fuse for the radio and 3 days latter,went out to start the car and it fired right up..Now I just have to figure out why the radio is draining the battery.This may or may not be the same problem you are having..Also the Msd box draws power directly from the battery.

shoebox

You need to hook up a meter set to amps and connected between the battery and ground cable and check to see if there is a parasitic drain. If you see a high number of amps flowing, pull fuses to isolate where it is coming from.

Powersource

I had the same issue with the radio. Amps would stay lit and drain the battery in a few days. Going through the previous owner's wiring this winter now that I have the interior redone.

Follow Shoebox's suggestion and run around checking everything with a DVM.

97 6SPEED Z

Do exactly as Shoebox suggests!

When you set up your ammeter in series bridging the negative battery cable and negative battery post, with everything off, you should see a current draw of only 60 to 70 milliamps, (i.e. that's .060/.070 amps). If you see a current draw any larger than this ........ start pulling fuses, one at a time, until you locate the circuit with the parasitic draw.

I had this same problem with my '97Z two (2) years ago, and it turned out to be an internal short in the drivers side power seat motor.

Also, if ALL curcuits check out okay, disconnect one battery terminal, (to take the entire battery out of the cars electrical system), check it's static voltage and come back two (2) days later, and recheck that voltage. If your static voltage drops by more than .15 - .20V ...... you have an internal short in the battery itself.

Good Luck!

mrmint69

I was just going to ask for a better break down of what to do. Thanks for the great info!! I know alot about cars, but the electrical is one I never had to deal with before. Besides shocking myself

97 6SPEED Z

Okay, since you are a self-admitted newbie on this electrical diagnosis stuff .......... you get three (3) more tips/cautions.

1) When I say "bridge" your ammeter into a "series" connection on the negative side of the battery, I mean disconnect the negative battery cable from the negative battery post, and then attach one meter lead to the, (now unconnected), cable, and the other meter lead to the, (now open), battery post. In essence what you are attemting to do is force all electrical current to flow through your meter ...... while measuring it. If your meter reads a negative number, simply reverse your leads and it will read a positive number

2) When you go to open your drivers side door to check the fuses on the drivers side end of the dash panel, be sure to quickly hold in the switch which activates the dome light. You can also use this test to insure you have your ammeter hooked up correctly. When the dome light activates you should see about a 5.0 - 6.0 amp current draw, still below the VERY common 10 amp maximum that most "cheapie" DVOM's have.

3) Finally, keep your ingition key in your pocket!!! If you inadvertantly try to "crank" your engine during this testing ........ you will FRY your ammeter, ( unless, of course, it's rated for over 100 amps DC).

Again ............ Good Luck, and let us know what you find.

Nickw059

I strongly agree with everybody's suggestions, its the best way! Also if you don't know much about amps, 1/2 amp is about equivalent to 1 lightbulb being on.

LaughingGravy

I don't appear to have any issue with battery drain on my car, but I did replace the battery last year and I'm keeping a close eye on what it does to make sure there is no issue. This is good stuff.:

This post is a thank you to all here who contribute, and especially to Shoebox, whose website and tech tips have saved me a bunch of money and provided satisfaction that most things can be done without the need to pay someone else to do them if there is the luxury of time and a place to do things.

mrmint69

I took a reading on the new battery before installing. I then went back two weeks later and it is 12.44 again, like the first time. Does this mean the car is not loosing the charge over time or is it necessary to check it another way? I still want to do the check like above, but the weather here is bad and I have lots of time before the car is back on the road.

rv93

so you had the battery installed for 2 weeks, and the voltage didnt drop? it sounds like you dont have a problem...lol

Rashiki

Wait, why are you leaving the battery in over the winter? Extreme temperatures negatively affect battery performance, and if it's sitting in cold weather not getting used, it's going to lose some juice.
I always take mine out and let her sit on a maintenance trickle charger on a wooden shelf during the winter.

mrmint69

Depending upon the weather, I still drive the car some. Sometimes it has to sit for 2 months and other times I have it out every other week. Snow can really mess with my cravings that I get, while it sits. The best part is how good it feels to drive, the first day the roads are dry Only sports car out usually. I figured the radio was slowly draining my battery, but it must have been the alternator not keeping it charged or a bad battery or both.

96 Z 28

I had issues with this over multiple years time though....

I figured it was the Alarm Light that was blinking, but any item that you can find that draws current will reduce the battery over the period of storage time.

My solution was to get a DellTRan Battery Tender

Works out awesome, as it has a plug on the end that you can switch out connections. They make a connect that hard wires to the battery, and all you do is pop the hood and connect to the Tender Unit. (See Pics Above)

All you need is to have a nearby power outlet (12 ft. I think for cord length, although I'm pretty sure they make an extension or you could extend it if needed).

Basically makes it a 2 second job to keep the battery charged when car is not in use, so much so I use it all year and not just during winter storage

Rashiki

Glad you live in an area where you can do that! Usually mid-october I put mine away for the winter and don't usually get it back out until very late march or mid-april depending on the weather.

I let it rain good two or three times once it warms up to drive it, I don't want the salt on her! I couldn't do what you do, it'd kill me!