tecart

i got back from vacation, it was 15 days, i didnt drive or start up the 86 944 turbo for only 15 days and i go to start the car and it wont turn over, all the lights are not working, no chime when the door is open, so i figure the battery is dead. I had just put a new 112.00 dollar porsche 944 factory mcdouglas battery in 30 days ago and it dead again. I did this only 6 month ago too from the last poshche battery dying too, so they replaced it under warrenty but now i got to do this again. I tried to jump it and it then starts up perfect on the first crank, i let it idle for 1 hour, then i drove it for 2 hours and got home, then i turned the car off and i go to crank it and it wont turn over, the battery isnt charging and its dead for sure as the volt meter shows only 10 and the lights are now dim and the windows go up like tortuses, slow. I then go to jump it and it starts again on the first try with my other car. Which mind you never dies even if i dont drive it for 1 month or more. Now i ask anyone, is it my alternator or starter or battery? the battery is dead for sure, it shows full charge with a battery charger but wont start unless i jump it with another car and battery cables then it starts perfect. I have gone through 3 batteries in 1.5 years now, the last lasting for 30 days, is it possible i did something wrong when i hooked up the arc2 or arm1 or maf#4 kit? or is it just ****ty porsche factory 944 replaceent batteries from mcdouglas? i know porsche said they will replace it again but why is this happening? i should be able to not drive the car for 15 days and then have a fully charged to start battery right? the starter is fairly new and the alternator is origional so any ideas, thanks Todd

Bri Bro

Go to a auto parts store that does "free" battery/altenator testing. I bet you find that the altenator is not functioning correctly. Also look at your battery connections.

951and944S

Most auto parts store that test "on car" are baffled when the can't attach clip leads to the wire from alt to battery, cause they don't even see the alt...!

If you can't remove it for testing, make it clear that they need to attach lead at wires going to the battery, AT the battery location just before the terminal..

Cheers

951and944S

Ooops Tecart, sorry i just reread your post, I assume it went dead not from driving but at a standstill.
If the battery isn't defective or been sitting on a shelf for an extended period then you may have a current draw...
possibly even a shorting power lead.
Try this, buy a testlight (cheap) charge the battery sufficiently, then remove both terminals.
Attach clip end to the removed positive cable.
Jab the positive post with the testlight.
The light will light if there's a grounded circuit, supplying the ground necessary to light the lamp.
Remove fuses until the light goes out to narrow the possiblities to aid in diagnosis.

From reading Beab's recent posts, I feel he's pretty handy in electronics, so by all means check the alternator first, then if the test I suggested concludes with no resolve, post back and let us know what's up...

BTW, if the alt. is defective, you CAN change the voltage regulator without removing the alternator from the car, I've done it, but you must feel your way....


Cheers

smokey

There's an article in the March issue of 911 and Porsche World describing a similar problem. The answer turned out to be the thermostatic switch for the radiator fan, which was activating the fan and draining the battery. I once had a problem with the thermostatic switch for the turbo water pump, but in that case you could hear the pump running all the time, and I caught it before it drained the battery.

Kevin M

[quote]Originally posted by tecart:
<strong>i got back from vacation, it was 15 days, i didnt drive or start up the 86 944 turbo for only 15 days and i go to start the car and it wont turn over, all the lights are not working, no chime when the door is open, so i figure the battery is dead. I had just put a new 112.00 dollar porsche 944 factory mcdouglas battery in 30 days ago and it dead again. I did this only 6 month ago too from the last poshche battery dying too, so they replaced it under warrenty but now i got to do this again. I tried to jump it and it then starts up perfect on the first crank, i let it idle for 1 hour, then i drove it for 2 hours and got home, then i turned the car off and i go to crank it and it wont turn over, the battery isnt charging and its dead for sure as the volt meter shows only 10 and the lights are now dim and the windows go up like tortuses, slow. I then go to jump it and it starts again on the first try with my other car. Which mind you never dies even if i dont drive it for 1 month or more. Now i ask anyone, is it my alternator or starter or battery? the battery is dead for sure, it shows full charge with a battery charger but wont start unless i jump it with another car and battery cables then it starts perfect. I have gone through 3 batteries in 1.5 years now, the last lasting for 30 days, is it possible i did something wrong when i hooked up the arc2 or arm1 or maf#4 kit? or is it just ****ty porsche factory 944 replaceent batteries from mcdouglas? i know porsche said they will replace it again but why is this happening? i should be able to not drive the car for 15 days and then have a fully charged to start battery right? the starter is fairly new and the alternator is origional so any ideas, thanks Todd</strong><hr></blockquote>

Tecart,
A couple things come to mind. Make sure that your hot wire sensor in your mass air is not wired directly to a hot lead. It should be wired such that it is hot when the key is turned in the ignition switch. Next, one of the diodes (I think) in my alternator is bad, when I start my car, I need to rev my engine (only once) to about 2800 rpm in order to get my voltage gage to pop up to just under 14. Once I do this it can go right back down to idle and maintain the same reading. If I don't do this it will only be at 10v and discharging until the first time I get the car up to 2800 rpm. Your alternator may not re-charge your dead battery. You jump start it and then drive it around with no problem. You start it up the next time and your battery is dead. Once you locate the problem, you may need to fully charge your battery on a charger. Lastly, I have heard there can be discharging issues related to the power window switches. This is not clear to me exactly, but it is something like you come in from a drive and park your car. You turn off the ignition and maybe have the drivers side window rolled down. You exit the car opening and closing the door. You lean back in through the open window and insert the key into the ignition and turn it enough so that you can check your gas gauge. You remove the key and go on your way. Apparently if you did not open and close the door, power is still being sent to the window switch and this can drain you battery.
I hope this helps,
Kevin

Perry 951

Get the battery tested. If it is fine, I say you have a grounding problem. Since you drive it fine, but turn it off and it does not start right away, it is very possible this is the problem. Nothing on the car will discharge a good battery in seconds.

Let us know!

tecart

well i dont got the maf or arc2 or arm 1 directly wired to the barrery so the is out, its wired for power in the fuse box to give power only when the motor is cranked, i used fuel pump fuse #34, so the lights are off the arc2 unless im cranking the car or driving it so that power robber idea is out. Next the car battery dies only if i dont drive the car for a long extended period of time like for 10 days or more and the battery is dead and wont start the car. But this time i jumped the battery to get it going and drove the car over 50 miles and 2 hours worth, then pull into my driveway, turn the car off, then quickly try to turn it over and it will not even click the starter and the volts show 10 or less on the dash as it will not power the to turn over, the battery isnt charging or didnt i drive it enough after 2 weeks of leaving it sit while i went on vacation
? Also while driving after jumping it, it drives perfect, all power works, and the battery volt meter shows 13.5-13.7 on the dash like it did when i first got it, but if i turn the car off im dead around 10 and it wont turn over and the car lights are dim and power is all drained? any idea

Bri Bro

Did you test the altenator? It sound like it isn't working correctly.

951Gary

Todd,
As you said ...
[quote] the battery is dead for sure<hr></blockquote>

Lead-acid batteries don't care to be deep-cycled (run dead). Even so called "deep cycle" batteries for RV's etc. don't really care for it. I've had RV batteries die after one accidental full discharge, while others of the same brand have survived several such discharges.

I have a similar battery discharge problem with my 951. Some day, in a fit of amibition, I hope to track down the current drain. Mine does not appear to be the glove box light, hatch light, fan, or turbo cooling pump that others have had trouble with. If I find it, I'll let you know what it was.

Your short battery life (on average) may be caused by many partial discharges. I'll speculate that a given battery might survive 3 really deep discharges, 20 half discharges, 200 discharges of 20%, and maybe 2000 discharges of a few %. Once filled with electrolyte and charged, lead-acid batteries live longest with the charge maintained. It is unfortunate for you and I that Porsche has produced (and we like)one of the few cars that seems to need a Battery Tender when not driven daily...

Gary

951Gary

I measured my current drain today. I was surprised to find that it's only 5 mA (0.005 A). A good battery can sustain that for 3 months with only a 10 A-hr discharge. This should not be a problem at all.

I'm now measuring the voltage decay of the battery disconnected from the car, as it does not appear that my 951 is draining the battery. I'm guessing that the battery has internal leakage. Either that or the car's current leakage is intermittent. This would be just my luck.

My battery is also relatively new (Interstate). The dash voltmeter suggests that the alternator is functioning OK.

I notice that there are many posts regarding 944/951 dead batteries. Is there something about our cars that kills batteries? Perhaps engine heat in the 951, but why the 944?

Gary

tecart

well the car goes in to the dealer today, they had me wait 4 extra days before i could get it in, and as i attempted to start the car, it was dead, the starter would not click at all and the lights were dim on the interior. So i decide to put a charger on it for 10 hours and it did nothing except give the lights more juice, the car again would not turn over and the charger did not budge at all from the first spot which was full dead. The charger next was used to try to start the car with its 55amp start option switch, again failed to turn the starter at all but now it clicks one time with each key turn to start it up. Next i simply put jumper cables hooked up to my other car to the dead battery in the car and didnt even start the good car up and then cranked my key once and it starts the porsche up on the first try. I let it idle for 30 min and turn the car off. Then i unplug the cables and again it will not turn over the starter. So i put the cables on again to my good cars battery without starting that car and wammo the p starts up again on the first try. Then i drive it to porsche and shut it off and show them it will not start again... Well they brought out a jumper portable one and it started on the first try. Ill know more in 1 or 2 days they seem to think its a drain on the battery and they will let me know but i think my battery is shot the alternator is bad and i got a power robber somewhere, any ideas to how my cars battery will start so easily with a good battery jump, can it be my alternator is killing my new porsche battery or not? If its the alternator who has the best price? and do i change the whole thing or just its voltage regulator? thanks and ill post more on this soon <img src="graemlins/crying.gif" border="0" alt="[crying]" />

cruise98

Todd:

Your battery is toast because it was probably sitting on the shelf with electrolyte for too long before being put into service and sulfated. Buy an Interstate or Autozone Silver or Gold battery. Unfortunately, you are in the warranty proration rut with the dealer supplied battery. Ask them to install a fresh one with just installed electrolyte. It should be slow charged after installation for maximum life.

That is my two cents anyway.

Keith

tecart

Well keith is exactly right on that one! thanks for the help on this, i got the car back today AND IT TURNED OUT 1 cell was completly dead in the battery and another one was real weak. They tested the alternator as good, and tested another new battery overnight to check for a draw on the system and if 9it turned out it was then i was out of warrenty on my 60 day old new porsche battery. Well next day the come to find no draws in the car at all, it was tested as about a 20 miliamp draw on my car and that they said is like a new car would do, anything higher then 50 miliamps means something is sucking/draining my battery as the car sits, so i guess i was good their too. They then tested the new battery they installed and didnt like its readings so they requested and got me a dry cell 999 type battery and filled it with fresh electrolyte and filled it and that did the job. Perfect readings, no draws, good readings with draws/loads on it too. So the car starts mint now, no need for jumps, the voltmeter on the dash shows 12 on starts and 13.7 while driving. So it could be that the cells sit on the shelf and the batterys are getting weak by themselves because not to many 944 in my area ever pay 125 bucks for the stock one and the ones ive been getting were on the shelf in the past. Now the test is to let the car sit for 10 days without driving it and see if it stats up??? Ill keep ya posted, no charge either and a free wash too

951Gary

Glad to hear that your problems are solved.

Mine however ... After 3 days of being disconnected from the car, my battery voltage dropped from 12.72 to 12.68. No smoking gun there. So I put a 4.5 A load on it for 3.5 hours, a discharge of ~16 A-hr. Voltage was 12.05, and started the car with no problem at all. Conclusion: battery is fine.

So it looks as though I have an intermittent current draw. Ain't I lucky?

Gary