i have a 1999 dodge 1500 2x2 the battery keeps going dead if it sits for a day? bought a ne w batt and checked alt tested fine checked cables and ground any help would be great

 

you'll need to measure current flow through each circuit, to identify which one is leaking current. there's a couple of different ways to do it depending on how much time and money you've got.

the slow, cheap way - remove a different group of several fuses each day. when the battery doesn't go dead, then its in that group. repeat the test with each fuse in that group to get down to the one that's the culprit.

faster way - use a multimeter that will measure current flow in amps and milliamps. one at a time, pull each fuse and probe the fuse sockets. test this on a known circuit thats drawing power, so that you know it works. a good example is a blinker with the switch on.

 

somtimes it starts sometimes not i took alt off and had tested they said it was good new battery and starter im lost help

 

do just as dhvaughan said. I'd do the multimeter if it were me and I guess you could do amps. I've always though about using volts with the key off, disconnect the negative power lead from the battery and put one of your leads from the voltmeter on the negative terminal connector, and the other on the negative terminal (battery). If something was draining the battery.... then with the voltmeter now in between the terminal and the battery, it should show around 12 volts. Pull the fuses one at a time until there is 0 volts and look into that circuitry for the problem. I just remember one time testing amps on a battery and this huge arc from one of the tester leads LOL, thats why when I get around to testing my fathers old car for the same problem, ill attempt the volt method.

 

That is the technique you would use to measure current. And I would be very leary of doing that. Most small multimeters have a very limited current capacity - say 10A. It might work OK with the vehicle off and nothing on...

The better way would be to find a clamp on current meter (Harbor Freight has some el cheapos for like 10 bucks). You would just clamp that over your positive (or negative) battery leads to determine current draw. This is much lower risk as the current is determined based on the strength of the magnetic field created by the flowing current. (ie nothing to short out).

In your setup... The multimeter could show 12V as you mentioned, but there will not be much current flowing because in voltage mode, the multimeter has a very high resistance.

As dhvaughan said... use a multimeter and measure current. Pull the fuse, put the meter inline for where the fuse was (setup to read current), and see how much current is flowing. If you find a circuit with a lot of current flowing - you have a place to start looking. However, as a word of warning, NEVER put the test leads between the battery posts with the meter set to current mode. You will get a nice spark show.

Another thing you can check... If you have any aftermarket audio amps... make sure they are not "on" all the time by having the remote terminal wired straight to +12V

Good Luck!
Cartman

 

since it takes his battery all day and night to go dead, that indicates that he's leaking out a very small amount of current, probably less than 1 amp, probably less that 1/2 amp. any cheap multimeter that measures current can handle this.

i don't think a current clamp will measure such a small amount. i'd think it would also be impossible to expose the wire and get a clamp around it.

i'd measure currents only at the fuse block where current is supposed to be.
DO NOT run high currents through any multimeter, especially anywhere around the battery terminals unless you want to learn welding.

radio, amps, security systems are good places to start.
nasty sludgy bulb sockets are another.