battery keeps dying

[an_corp09]

i have already replaced the battery once and then replaced the alternator. the car can be jumped and will run fine that way but it will not start on its own. i have no idea what it could be i haven't had the z for long.

[240Z-Fan]

Ben,

There have been numerous discussions as to how to diagnose this sort of problem. Search the forums to see some good diagnostic suggestions.

Alternately, go to a local Sears store and have them check out your charging system. They have a really great tool that can diagnose the electrical system. Best of all, last I recall, it was only $10 to have them hook it up.

Call them to verify thie price before going, but this may be the best way to know where to start. Then come back and let us know what you found; we can help you better once we know more.

Al

[mally002]

I had the exact same problem, it was my alternator and voltage regulator.

Even though you put a new alternator on have it checked, you could have received a bad one.

Good Luck.

[DeesZ]

Any of the mentioned components can be bad (even right out of the box), but do not overlook the battery cables themselves. I had a series of problems that was solved completely after replacing them. I guess they tend to corrode and deteriorate internally under the insulation where it cannot be seen. ....the best $20.00 I've spent on my car yet....

[76Datsun280z]

Alternately, go to a local Sears store and have them check out your charging system.

On a side note, don't take it to sears for your Z's sake, they don't know what they are doing, nor do their "mechanics" speak English!! I took my Z there about a year ago to have them install a new battery and they reversed the battery cables when installing the new one all which caused a big ordeal and we had to take it to an electrical shop to have the electrical damage fixed all of which Sears payed for of coarse. I'm not ever letting them touch it again, or any car for that matter.:nervous:

[Zs-ondabrain]

You did'nt say if you replaced the (VR) Voltage Regulator or not. What year Z is it?

1) replace the battery cables and double check all the grounds (one on the firewall near the battery and one below the battery but above the frame. Remove and clean all the grounding areas and terminals then replace and tighten down.

2) never replace a bad alternator in a 240Z without replacing the Voltage regulator. (Rule of thumb)

3) have you installed any 12 volt items lately that might be drainning the battery? ( lights, radio, upgrades? anything) Any recent work on the car that may have interupted a ground or shorted something out.

4) with Nothing on, doors closed, key off, pull the (+) battery terminal, wait for 10 seconds, then slowly bring the battery cable back to the battery post and watch for a spark.

If there is a spark, there is an obvious short somewhere. Disconnect the VR and try it again, if the same spark apears, reconnect the VR then disconnect the alternators power wire and 2 terminal "T" plug then try the battery post again. Repeat the process with the starter wire that goes to the engine harness, different fuses in the fusebox, etc, etc.

This should help you eliminate one thing at a time. Process of elimination. You'll learn more about your Z and save money at the same time.

Dave.

[sblake01]

On a side note, don't take it to sears for your Z's sake, they don't know what they are doing, nor do their "mechanics" speak English!! I took my Z there about a year ago to have them install a new battery and they reversed the battery cables when installing the new one all which caused a big ordeal and we had to take it to an electrical shop to have the electrical damage fixed all of which Sears payed for of coarse. I'm not ever letting them touch it again, or any car for that matter.:nervous:

Okay, so you had a bad experience at Sears. That doesn't give you cause to denigrate them based on the language that someone speaks. I really wouldn't have expected that from you. You got your car fixed and they paid for it. Chalk it up. "They" didn't reverse the battery cables, one person did. I'm sure if you went there again, they'd remember you and you wouldn't have that type of experience again. Though reversing the battery cables is a stupid mistake, the origin of the person that did it has no bearing on the situation. But I'll bet that the fact that Sears had to pay for the repairs probably had a bearing on his employment situation.

[SteveJ]

FYI The original poster's car is a ZX. I attempted to reply to his original post yesterday (placed about an hour before the start of this thread), but the electrons vanished into the ether when I tried to post my reply. The good news is that I can now add to check battery cable resistance to my list of diagnostics.

[DeesZ]

On topic: Great advice offered by Dave for working towards a fix. In a good order for approach as well. I will underscore his first suggestion with the cables and grounds. These two things are issues that you will need to address before you can expect anything else to work properly, and trust me, looks can be deceiving. I continue to be amazed by the issues that disappeared after I addressed those two issues.

Off topic: That's a pretty hard slam/generalization/stereotype on Sears based on ethnic grounds... Heck, I speak English as a first language and have made some pretty stupid and costly mistakes in my lifetime.

Several of the absolutely best mechanics that I have known spoke very little English. Trust me, I have gotten some of my worst work done by true blue Americans... does that make them all loosers? If so, I will have to rent a backhoe and exhume my old friend Hans who got his training by the Third Reich.

[sblake01]

Also, if you scroll down to the bottom of the page, there are two similar threads, 'Battery keeps dying' and 'Battery Dead after a few days', that addressed this type of problem last year and three years ago. They might also be helpful.

[240Z-Fan]

Well, while I am not a fan of most chain-type repair shops, the tool that Sears has is really great. I wouldn't mind having one in my tool collection.

The neat thing is that it is non-invasive, much like a voltmeter, it clips onto the battery terminals and has an inductive probe that clips on one of the leads to monitor current.

The software performs the diagnostics and reports back with a determination of bad alternator (rectifiers or voltage regulator), bad battery, i think even bad starter.

If the price is anywhere near ten bucks, it is well worth it.

Ah yes, English is my 1st or 2nd language depending how you look at it. Either way, bad mechanics are just that, bad mechanics. Stupidity is not bounded by race, or ethnicity. It seems that the chains tend to attract them as they may be cheaper than really competent ones.

I have done my own work since I started driving with very rare exceptions in about 25+ years. One recent exception (of two in 15+ years) reinforced my belief that I should do my own work... or find the one mechanic I can trust.

However, in this case, the time savings and low risk may be well worth the trip to Sears.

Al

PS In all fairness, I wonder if the language reference was more about being able to communicate the problem to the mechanic, not that he/she was in some way inferior due to their inability to speak English.

[76Datsun280z]

I'm sorry about that guys, that came across a little racist.

When it happened, my dad and I tried to speak to the mechanic about what he did and we really couldn't do to his English. I wasn't trying to imply that people from an ethnic backround are bad mechanics, but rather from my experience you can't speak to the mechanic about the work he is doing on your car which in opinion is pretty important I guess.