First off I'm a new member, so thanks for letting me in. I have a recently joined the Porsche family with my 9mo old to me 1987 924S It is a great
car in great condition, and I haven't had any problems with it until recently. Last time I took her out she started hesitating when I put the gas to it, and it seemed to get worse and worse. (That was not right away, but after it had run fine for several miles) Looking at the voltage meter (had previously been changed out where the clock usually is) it was visably falling. Finally it died all together. Nice looking Porsche setting on the side of the road with the hood up. (Not a pretty site) Anyway after hooking up a battery boost charger to it, it started right up and ran fine back home. I could see the the volt meter has going down though.

What is the problem, what should I check?
The battery is fine, had it checked and it recharged no problem. The alternator is nearly new less than 300 miles on it I would say (replaced before I got it), and the belt is tight, and everything seems to be connected corectly. I checked the battery cables, and all connections on wires. all is good.

I am afraid to take it back out for fear of the same thing happening, although after checking, and recharging the battery it starts right up and runs find setting still.

If you have any suggestions they would be appreciated, and if you need to know anything else let me know.

Thanks,

 

With the car running check the battery voltage with a multimeter. If it is below 13 volts while running chances are your alternator is not recharging the battery. Was the battery load tested? I would bet on the alternator.

 

Thanks,
I will do that, and report my findings.

 

Agreed with simxxi, i must give +1

 

Well........I am getting 13 volts on the multimeter with the car running.
What's next?

 

well i agree with you and your post it happens this is general and common to all !
some time we also face this !

 

Any more sugesstions?

 

Check the battery voltage with the engine running. Increase the RPM's does the voltage start to drop? Not the interior car voltmeter, an external voltmeter at the both leads of the battery. If so Alternator, has the battery been "load tested" at the auto store?

 

Thanks,
I'll get on all of this next week, and report back as to my findings. No the battery was not "load tested" so I'll do that first to eliminate that item.

 

Well, sorry it took me so long to get back to this........
But I have had surgery in the meantime, never fear all is well.
Ok, so I desided....it has to be the alternator even though the last one
was changed out in 5/10, now it is 10/11 on this new (rebuilt) one.
Is there anything that could cause one to go bad in perticular? I realize
it is a mechanical part, and subject to almost anything.

The prior owner had changed out the clock for a voltmeter. I think it needs a new ground, as the needle moves around a lot. Any sugestions or should any solid ground do the trick.