Starting Problems -

[gbabcock]

I'm wondering what might be going on, as I have no clue. My Z had been sitting for about a month and over the pass week I had to jump it a couple times and it seemed as though the battery was not holding a good charge. Yesterday, just to make sure, I charged it up, drove the car for about an hour and this morning went out to start it and got no power - not ever guage lights. I then proceeded to go and get a new battery - but after putting the new battery in, the same thing happens. I've checked the most obvious things - the cables are connected to the right terminals ( and both cables are fairly new as well), the starter is also fairly new. Any ideas on where I should look? - thanks

[Nissanman]

When you say "the same thing happens", I assume you mean the car starts, runs, but when left overnight the battery goes flat.

There may be a load on the battery even when you turn off the key.

That is easily determined, and avoided, by disconnecting the battery terminal after you shut the car off.

Next time to start it, re-connect the terminal and see how the battery performs.

Barring another stuffed battery, it should be alive and well.

Once it starts, you need to check the charging function of the alternator.

See: -

http://www.classiczcars.com/forums/showthread.php?p=211105#post211105

If there is a load draining the battery overnight, you need to investigate as what and where.

It might be as simple as a radio/tape player or rear de-mister left on.

Fuse pulling is the quickest and simplest method to narrow it down.

Then you might have to go to plug pulling etc.

A car will run for quite a while on the battery alone and the alternator alone for that matter, until you try to restart it:tapemouth

[hd240z]

Sounds like you have power drain somewhere in your car when the switch is off. If you have a hand held meter available to read the amp draw from the battery, its possible to locate the problem by pulling the fuses one at a time and see if the amp draw stops or decreases to a few milliamps. At least that will narrow down the problem to a certain circuit to check.

Even without a meter you could pull all the fuses and see if that eliminates the problem, then replace them a few at a time until the problem returns. If pulling the fuses does not stop the draw your problem may be with the alternator, ignition switch or something not wired through the fuse panel.

Good Luck

[SteveJ]

Of course, the charging system itself can drain the battery. About 12 years ago, I was having problems with the battery draining. A friend suggested checking the voltage regulator. Sure enough, the current draw stopped as soon as I removed the voltage regulator. I replaced it and never worried about it again.

[SteveJ]

Sounds like you have power drain somewhere in your car when the switch is off. If you have a hand held meter available to read the amp draw from the battery, its possible to locate the problem by pulling the fuses one at a time and see if the amp draw stops or decreases to a few milliamps. At least that will narrow down the problem to a certain circuit to check.

Even without a meter you could pull all the fuses and see if that eliminates the problem, then replace them a few at a time until the problem returns. If pulling the fuses does not stop the draw your problem may be with the alternator, ignition switch or something not wired through the fuse panel.

Good Luck

Gosh, it seems like so many people are quick to pull fuses. What fails "on"? For the life of me, I can't think of anything. Something close might be a short in the ignition switch that makes it where you're not cutting off power when you turn off the car.

The fuse pulling method is needed ONLY after eliminating the charging system as the culprit. Next, instead of pulling fuses willy-nilly, focus on systems that have changed such as a new stereo/amplifier, a car alarm, or other electrical accessory that has been added. Also check the stupid stuff like the dome light and glove box light. If the glove box door isn't closed and the bulb is good, it will drain the battery.

[280~Master]

Do you have the internal or external regulator?

I have to go with Steve on this one. Check the Alt then look at the voltage regulator. Replace as needed.

[beandip]

We pull fuses because this is the easiest start to find the problem. Cost zero to remove a fuse. If you have a multi-meter disconnect the neg battery terminal and connect the meter and see if there is a draw. If there is , then watch as you remove the fuses when the draw is eliminated you know where to chase down he problem. Gary

[EScanlon]

Or use the "poor man's" multimeter... a light bulb.

Put the bulb wiring in series with the negative terminal and the ignition off. If it lights or even just barely glows...there's current flowing through it. This won't be effective for really low currents, but they won't drain your battery overnight either.

Gary's fix works as long as the culprit is on a fused circuit thorugh the fuse box and not on it's own in-line fuse or even an un-fused circuit.

The regulator is also a good candidate, and it wouldn't be on a fused circuit.

FWIW

E

[gbabcock]

I think I didn't clarify something very well - the new battery - with a full charge, won't start the car or get the gauge lights on; this happened directly after putting the new battery in. I was thinking along the lines of the alternator as well, but when driving it, I never seemed to lack any elec. power (dim lights, etc.) at low rpms. The only other thing I can think of is that my electric fan is coming on too much, as it will turn on after the car is off and it has been hotter than normal - though that would not explain why the new a battery doesn't work? Thanks for all the replies.

[SteveJ]

You may want to post your events in a chronological fashion. What happened and when? It's a little confusing to see tidbits of information scattered about.

Since you say your new battery won't start the car, have you checked your fusible links?

[gbabcock]

That would make sense - here's a rough order of events:

Car sat for about a month (on vacation - it doesn't get that kind of neglect when I'm around).

Jumped it, ran it - everything appeared OK.

A couple days later, I went to start it, but the battery was too weak to turn it over.Charged up the battery very well, drove around for about a hour. I let it sit over night, came out the next morning, tried to turn it over and got nothing - not even gauge lights. Assumed a new battery was in order.

Picked up a new battery, put it in and tried to start it, and again nothing - not even gauge lights. Checked the stupid stuff - cables are going to the right places, starter is fairly new, cables are new, ignition fuse is OK. The only thing I can think of is my electric fan, which tends to run for a while after the car is shut off (particularly when hot - as it has been) - yet that wouldn't really explain why a new battery wouldn't work directly after being put in?

[gbabcock]

I'm not quite sure what 'fusible links' are (forgive my ignorance).