I noticed the volt meter was at zero the other day but it was day light and the car seemed to be running fine. Just figured the volt gauge was on it's way out. Car sat for a few days and then took it out for a spin tonight. Car started right up (As she always has - no matter how long she sits) but noticed the volt meter was at zero again. I don't drive the 928 much at night but it seemed like the dash lights were dimmer than I remember and so were the headlights. As I drove some more it seemed the headlights were getting more and more dim. Finally the were out completely. I turned around and headed home. In blackness. Got to my driveway and the car died right as I pulled into my driveway!

Tried to start her up, but totally dead. Luckily I was in my own driveway so I got the charger out and set it to car start mode. A few minutes and she started up but started going dim real quick. Volt meter was at 10. Got it safely into the garage and she's dead again.

I've had this 928 for 5 years and never changed the battery. I started wondering recently if that was due. So tonight I opened up the rear battery compartment and the Interstate Battery is dated July 2005!

Easy enough to change the battery compared to my Ferrari Mondial - where you have to remove the front wheel to get the battery out.

Just wondering if I might be facing a alternator or grounding issue at the same time. Any thoughts based on above symptoms?

Last question is a quick refresher on changing the battery. Hook ground up first or positive first? It's been a long, long, long time since I changed a battery on a 928

 

You might be having issues with your alternator's exciter circuit. Do you have a voltmeter?

 

Connect the positive first - the fit for that is usually more critical. The ground strap goes on quicker.

Clearly you had an alternator issue (reason the battery died) and also some kind of connectivity issue to the pod or voltmeter. I suspect a connection to the pod was lost and you therfore lost the exciter line to the alternator... Possibly the alternator is still OK or maybe not (could be the cause) - but you have some other issues for sure that killed the last battery...

If you don't fix it soon your new battery will be dead - it will not survive deep discharging even if new.... disconnect whenever possible and don't drive it much like this... just to get it fixed

Check the pod connections & fuses.

Alan

 

Was afraid it wasn't just the battery, but I was hoping so. Guess if I was going to kill a battery might as well have been a 9 year old battery. I'll get it flat bedded to my mechanic. and have them sort it out.

What are the best case/worst case costs I can expect for the likely culprits?

 

Most likely culprits? What Alan said.

9 years? Outstanding.

 

Well - worst case ifs probably an alternator (new or just rebuild) and perhaps some investigation and refresh on the pod etc connections...

It may just be a simple connections issues - but can be expensive to diagnose. Have your mechanic trace the exciter wire from pod to CE to jump post to alternator and see where it has an issue, also have him look at why the voltmeter ever reads zero? Check fuse #12 yourself?

Alan

 

Thanks. Will do. I'm traveling so will dig into it mire when I'm back home.

 

I've had the battery on a charger. Something I've never, ever needed to do BTW. Started right up and I took it for a short ride. Volt meter still not working. Window's running real slow. One additional symptom now is that the cold start is staying on even after warmed up. i.e. high idle. (Never an issue before). Any thoughts on the combination of the apparent charging problem?

I was in China for two weeks and now my mechanic can't take the car 'till this weekend. It's just been sitting on the charger. I was planning to flat bed it to him but he thinks I can make it in daylight with no power accessories running. Took it out for a ten minute drive to see if he's right. He's thirty minutes away though.

 

This is when AAA premium is nice, 100 miles towing, no reason to think about it.

 

Wouldn't the 14 Pin connector be a good place to start and at least clean?

 

I would suggest the Pod is the place to start - two known issues here: voltmeter and alternator exciter: common point -> pod.

Alan

 

Car will go in for service this weekend. She's just been sitting since the first sign of trouble including the decade old battery which will be replaced. Just put it on a charger to hopefully juice it up enough to make it to the shop.

Just wondering if the cold start is connected to alternator, exciter, battery issues as I didn't think they would be connected.

I'll have it all checked out and cleared up. Thanks for the attention points - just wondering if cold start not coming off after warm has some trouble spots to look for.

Thanks for your help!