All electrics died after putting air in tires - WTF!?

[Spice_Rack]

I've had my 2004 Nissan 350Z for about 1.7 years now, got it at 44K miles and its now just over 70K. I've had no problems with it except overheating when at the track but I still haven't tried to fix that yet. Regardless, here's my situation I need help with...

I stopped at a service station two days ago to put air in my tires as one was especially low. I left the car running while I did this and when I was done got back in the car. Right after I sat down and was about to put it in reverse the car just shuts off, everything... off. I put the key to off position and moved it back to on... nothing. I took the key out and tried to lock/unlock on the key FOB, nothing...

I pop the hood/bonnet and check the fuses on my battery which looked fine. So I figured i'd try to shimmy a battery connection off the terminal and reconnect it. I did this with the negative cable as it wasn't super tight, having it off for about 5 seconds time. I then tried the key FOB and it is locking and unlocking fine now. I get back in my car and it starts up fine. I continue swearing and drive home.

It's been two days now and I haven't had this problem since. However, i've been noticing now just after coming to a stop, that sometimes the revs drop to ~400-500 RPM. I've only noticed this a few times though. I also noticed today though while the engine was running, my voltmeter read 15.5 V which seems quite high. I try to check the voltmeter every once in while and it is usually right on 14 V. Other than these things, everything else seems to be normal.

Now I did change the battery with a cheapo one a little over a year ago because I started getting slow cranking on engine startup and the battery didn't seem to be charging. The new battery fixed that of course... and I also replaced the belt for the alternator/generator. However I wasn't able to get the belt at the correct tension I think because when it is cold outside (below 50 deg F usually) and the engine is not already warmed up, the belt squeels like crazy for a few seconds. It is particularly worse if I put the soft top up or down which would be drawing a lot of amperage i'm sure. I've had two mechanics check the belt tension, one of which was a Nissan tech at a dealership and both said it was fine.

So anyway.. feedback, ideas, or suggestions would be nice. I'm considering just replacing the belt... easy to do anyway and maybe the one I bought is just crap.

[Adunaphel]

I'd suggest posting this to a 350Z board (there must be tons of em), or just taking your car to the dealer and let them have a look at it.

[matt2000]

You know, when I saw "All electrics died after..." on the main forum page, I was almost certain this thread would've been started by Argatoga.

[narf]

I don't know any figures, but I figure the AC, headlights and radio will consume significantly more than the soft top.

For comparison, an electric garage door opener might use 200W - your soft top should be easier to open/close than a garage door.

[airmenair]

As far as the electrical matter goes, it definately sounds like/was a poor connection at the battery. Sometimes that happens without any real provocation. I've had it happen to me, even when the leads are tight on the battery. Sounds like to me you've basically fixed that issue.

As far as the rev drop goes, maybe you're electric fan was kicking on? Do the RPMs shoot right back up or do they stay low?

I take it you were reading across the battery terminals. Were any accessories on, electric fan, a/c, etc? That might kick up your RPMs and make the alternator pump some more voltage.

Have you tried re-tightening the belt?

[MrBooby]

It was the def the battery connection.

[FATMOUSE]

Yeah, I really did think this would have been posted by an MG owner or something.

Or maybe Spectre and his Jaguar?

[Spectre]

Wouldn't have been me - remember, I (re)build Jaguars, so I wouldn't exactly have been in here asking for advice.

Original poster - I second the battery connection suggestion, I also believe that you should have your battery tested for a bad cell. Clean your battery terminals soonest (and get the battery tested), before you fry your alternator or some of your electronics.

[Spice_Rack]

Thanks for the responses fella's!


Adunaphel, I did post this on a 350Z board a few days ago that I frequent but haven’t got a response… but unfortunately it seems to me that half the guys on the forum are just tools and don’t know much about mechanics anyway.

I don’t want to take it to a dealership unless I have to out of desperation. The last time I wanted to get something like this diagnosed they wanted $125 USD


narf, the AC was off, headlights (xenon) don’t draw that much energy except on ignition, and the radio is stock so not much energy use there. There are five motors for the electric operated soft top and you can tell it draws a lot of amperage when putting it up/down by the way the car reacts. Putting the top up/down does something to the alternator/generator because it squeals like crazy the entire time. Giving the engine a few revs helps a bit but isn’t nice on a cold engine. If I don’t put the top up/down on a cold start it only squeals for about half a second then stops. The headlights nor the radio change this.

The electric garage door opener in my car on the rear-view mirror is a simple radio signal being transmitted… I doubt that uses much more energy than the key FOB. Where do you get 200W from? Do you have a beefed up transmitter to open/close your garage door from 50 km. away because then I can see 200W being needed for that.


airmenair, I can certainly tighten the battery terminal connections, but it has been like that for more than a year without problem. And would the car even shut off if the battery got disconnected? Doesn’t the alternator/generator supply enough energy to keep the car running? I thought the battery was only to supply electricity for the starter motor.

As for the revs dropping I doubt it would be the electric fan. I’ve heard it come on hundreds of times while sitting in traffic and the revs never dropped because of it. The RPM’s come back up after just half a second or so and stay at normal idle.

I have not tried retightening the belt, I may try that…

Spectre, I can certainly have the battery tested… would a bad cell cause the alternator/generator to try and increase power output in order to charge a battery that it senses is low? The battery terminals and leads are clean as a whistle, no corrosion on them at all.



Guys, I think I will try tightening the battery terminals, maybe retighten the belt and/or replace it. If that doesn’t help I will probably try to take it to a local garage to check the battery and generator.

[Spectre]

Yes, a bad/internally shorted cell could cause that.

Also, about most people on car forums being tools and not being people who use tools instead - well, that's pretty common. It's rare to come across one that isn't.

[_HighVoltage_]

Spice Rack, did you open the tops of each battery cells to see if there is fluid in them? Check that if you haven't.

(with everything turned OFF...duh!

[argatoga]

Originally Posted by FATMOUSE

Yeah, I really did think this would have been posted by an MG owner or something.

Hey! My electrics are fine, well mostly, ok ... shutup!

[FATMOUSE]

On a serious note, maybe something going to ground somewhere in the maze of wires that is a modern car?

[narf]

Originally Posted by Spice_Rack

narf, the AC was off, headlights (xenon) don’t draw that much energy except on ignition, and the radio is stock so not much energy use there. There are five motors for the electric operated soft top and you can tell it draws a lot of amperage when putting it up/down by the way the car reacts. Putting the top up/down does something to the alternator/generator because it squeals like crazy the entire time. Giving the engine a few revs helps a bit but isn’t nice on a cold engine. If I don’t put the top up/down on a cold start it only squeals for about half a second then stops. The headlights nor the radio change this.

The electric garage door opener in my car on the rear-view mirror is a simple radio signal being transmitted… I doubt that uses much more energy than the key FOB. Where do you get 200W from? Do you have a beefed up transmitter to open/close your garage door from 50 km. away because then I can see 200W being needed for that.

I mentioned AC, headlights and radio to illustrate that regular electric power consumption should be higher than what the electric roof needs.

By electric garage door opener I was not referring to the transmitter in your car but to the actual actuator (pun intended) inside the garage.
I'd gotten the 200W from here http://www.aufinger.de/pdf/ma150.pdf
http://www.grollsystem.de/website/ca...orantriebe.PDF claims 150W for a double-width garage (max 6m), should be significantly less to open/close your roof.



I'd say the roof causing squeaking etc. are only symptoms, not the main problem. No point in guessing what exactly it is without seeing the car belt, generator, battery, ...

[GRtak]

Originally Posted by Spice_Rack

I've had my 2004 Nissan 350Z for about 1.7 years now, got it at 44K miles and its now just over 70K. I've had no problems with it except overheating when at the track but I still haven't tried to fix that yet.

It doesn't look like you take advice anyway. That overheating problem could kill your engine.

[Spice_Rack]

Originally Posted by GRtak

It doesn't look like you take advice anyway. That overheating problem could kill your engine.

Why would I ask for advice if I didn't take it? That's silly... I haven't done anything with the overheating issue because it only occurs on the track, and I haven't been on a track since then so there is no reason to try to fix something that isn't a problem at the time, nor will it be unless I take my car back to the track. I will attempt to fix the problem before I do that though.

Anyway I will try a few of these things this weekend sometime... starting to get cold and when that happens I become extremely lazy and don't want to do anything.

[GRtak]

You went to the track after that advice was given.

[Spice_Rack]

Actually most of the responses were after I went... I wasn't even sure if it was going to be a problem on the track. Anyway what are you trying to prove? You find it necessary to be a dick just because I don't instantly go try every single response I get? I like to learn everything I can from everyones responses and will then try some of them when I feel it necessary.

Thanks to everyone who responded i'll let you know what the fix was once I finally get around to getting off my lazy ass.

[jayhawk]

I work in parts at a Nissan dealer, and I have never heard of this happening to a 350Z, though I can attest that it has nothing to do with your tires. You would not think so, but they are pretty simply laid out and designed, UNLIKE the 300ZX's before them.
I have never once handed a tech a starter or alternator for this vehicle, so I am thinking you may just have a battery that needs replacing. Typically on Nissan's you get 3-4 years out of a battery.

[Spice_Rack]

Thanks for the info jayhawk... I've gotta try a few of these things first before I'll know. I've only had the battery about 1.3 years though, but it was a cheapo one.