I can`t find whats draining my battery over nite and preventing it from starting in the morning.?

Question

About a month ago my 1999 S-10 4x4 engine cutout while I was driving, I replaced the fuel pump & Filter and it ran fine for about a week. Then I started noticing the engine was hard to start in the morning, until one day it would not start at all, I thought it was the fuel pump again, but I went ahead and gave it a jump start and it started right up. I bought a new battery and had the alternater tested. That didnt fix it, I hooked up a multi meter from the ground on the battery to the ground on the truck and it is reading 12V, Isnt it suppose to read .05? I left the multi meter there and pulled all the fuses under the hood and in the cab, and also pulled the wires off the altenater, nothing changed the multi meter reading. I just tested my battery today with the multi meter and it reads 12V, shouldn`t that be enough to start the engine? Why do i need a jump start every time? I`m lost, Please help

Answer 1

check your alarm system back up batttery or your rear screendemisteris turning off with the ignitio switch turn on your headlights with the ignition off on see do them go dim on there own also the central locking may be faulty something is not switching off

Answer 2

You might try this one. Disconnect the Negative Battery terminal. Now take a 12 volt test light and connect it between the battery terminal and the negative battery cable. This will not " hurt" anything or ruin the light etc. If the light is on ? That's an indication of something in your vehicle is on.....if there is an under hood light..take the bulb out....start taking fuses out of the fuse box....might take the " Dome" light fuse out first.....cause you'll have the door open and the light will be on bright ( test light ) when you disconnect a fuse and the test light goes out....then that the circuit that's got the draw or short...or something that's on all the time. I have seen Cigarette lighter go bad and be drawing enough voltage to kill the battery over night.....hope I helped. Good Luck.

Answer 3

sounds like you may have pinch a wire when you changed the fuel pump . 12 volts is right that is what your battery is rated at the reason you get 12 volts and the battery is week is because it does not have enough amps on charge to turn the engine over . also i would check for lights that stay on . like a glove box light or an under lighted hood . your battery connectors could be against the side of your truck lid . if every thing else is OK you could unhook the battery every night until you can have some one look into the matter for you

Answer 4

first to find a voltage drain you need to use a test light, its more accurate, and it needs to be inline with the negative battery cable, in other words remove the negative battery cable from the battery and put the test light inbetween the two, then remove the fuses one by one and see if the light goes out

second do a voltage test at the battery and then at the starter, this will give you a voltage drop. also check the voltage of the battery during cranking but make sure the battery is fully charged

test the charging system running, turn all accersories on and see if the alternator can keep up, you should be able to maintian 14.3 volts or more during this test

most important check all your gounds and check for battery voltage at the back of the alternator ( the big red wire)

hope this helps

Answer 5

i own a repair shop,and that should be more than enough to start it,,and since you already did a draw test on it the only thing i can think of would be a accessory item that's running it down like that ,i just repaired a Nissan this week that had a hatch that wasn't closing all the way on it,,it liked a 1/16,th of an inch making the rear light go off,so you see it doesn't take much t run one down,,id try going over it again ,there has to be something staying on that's doing this,,it can be a glove box light causing it,,just re-check it,and if you don't find it,i,ll do some research,and see if i can come up with something here,,good luck i hope this help,s.

Answer 6

First thing test lights can`t be used to ck drain on computer controlled vechicles.This just adds resistance to the circuit and keeps the test light on .Bcm,s and Pcm,s will stay awake and give false indication of a constant drain on batt,use multimeter set on amp scale between neg cable and batt Be aware that any drain on batt exceeding 10 amps will blow fuse in most meters.

Answer 7

If there is power between the negative on the battery and the body/engine ground, there is something seriously wrong, since the negative on the battery is connected to the engine ground.

Answer 8

i'm not sure why its doing that, my Trans am had alot of shorts though and the battery would drain.

But while your trying to figure it out....i suggest going out and buying a battery disconnect switch (one that mounts on to the battery itself) to save the juice left in the battery. or u cud just disconnect the wires from the battery each time u shut the car off.. but the switch is easier

Answer 9

You have done a lot of very good tests the only thing i can see you have not done is disconnect the starter when you have your meter hooked up i have seen a draw in the alternator in the past as well..

Answer 10

you need to connect the multi meter on the 15 amp setting the computer and radio will draw about .5 amps,pull fuses untill you get that.right idea wrong setting.good luck