Battery Keeps Dying

[islandtuner242]

Ok every so often my car's battery dies on its own i'm thinking it's the alternator but if i start the car and take the battery cables off it still stays on an ideas....... i was also wondering if someone could help me understand how the cables run.... i notice i have 2 cables coming from the back of the engine(most likely by the alternator) and what looks like a ground cable coming from the passenger side under the hood can anyone help me out here .......... soon as i get my phone charger i'll post a pic

[marty1mc]

First, when is it dying? Is it dying while it is running or when it sits?

If it is when it is sitting, then it's not likely the alternator. You either have a bad battery or a drain on the battery that is causing it to discharge. Have the battery tested.

If it's dying when running, then the alternator may be the problem. Check the voltage while running at around 1500 rpm. It should be between 13.2v and 15.0v. Next, turn on the major accessories (heater motor, lights, radio) and check the voltage again at 1500rpm. If it stays between those limits, you should be ok.

[islandtuner242]

Thanks.....Also any idea on how the cables are supposed to be run, the previous owner had alot of wires "custom" in the car

[marty1mc]

Which cables are you referring to? There are a lot of them.

[islandtuner242]

Sorry for the late reply..........here is the link of a video i recorded about the battery cables..... Please help
http://www.youtube.com/watch?v=coizhdnUpIk

[marty1mc]

I would get a new battery harness and clean up the area where the ground hooks into the firewall. You can get a new battery harness from Z1 for $74. Then make sure you hook it up properly and hook up the ground side to the battery after all other connections are done. Next, I would look to clean up the additional wire on the positive side (it runs to the fusible link box). Find a good connector and crimp it on properly.

From the video, it also looked like the ground hooked to the transmission was very loose. If that is the wire, the new harness will fix it. But, that should be tight to provide a good connection.

Hope this helps...

Marty

[islandtuner242]

thanks and by the way the wire that runs to the fusible link....should i reconnect it like it is now or leave it out?

[marty1mc]

The wire that runs to the fusible link runs everything. You need to reconnect it.

[islandtuner242]

thanks marty1mc......i spoke to my neighbors dad (a certified mechanic) he pointed out worse case scenario it could be the voltage regulator so i'm going to remove the alternator tomorrow and get it tested when i could

[jona300zx]

You should check the battery first before you go through all the wrok of removing the radiator

[rjnissan93]

hey guys, im new to the "nico" forum & i really appreciate everyones input since ive joined. im also experiencing a slow battery drain on my 93 300zx so since the battery was close to dead, i just replaced it. the slow batter drain continue after sitting about a week so over time i had 2 mechanics check it out & they obviously eliminated the battery because it was new, & also eliminated the alternator.

just for a piece of mind i replaceed my old alarm because it was about 8-10 yrs old so that eliminated that being a possibility....lol. keep in mind i dont set my alarm when my car is in the garage, but after about a week my battery was low again. now, what i found out was that the battery was never going completely dead, however, it was just drained low enough where it did not have adequate chranking amps to start the engine.

so im begining to look at other aspects for the slow drain.....power antenna, driver side power seat, etc. well, i like what some mention b4....add the amp/volt meter to the circuit & do the old fashion way of process of elimination with the fuse box!! i feel like ive done all i can do, so does anyone else has a better ideals, or suggestions.

thanks all u cool z guys.....