Battery drain or something else

[eyal928]

I have had a continuous problem with my 1988 S4. It runs beautiful but the battery seems to drain if I don't start it after a day or two. My mechanic kept the car for a week and ran tests and told me the amp meter did not show any sort of draw all week and that he did not have any problems starting it. I picked the car up Friday night, drove it saturday and by sunday morning the trouble began again. I turned the key in the ignition and I hear a clicking sound. The motor started to turn but it would not start. Finally I jump started the car and it worked again.

Does this issue necessarily have to be a battery drain or could it be something else? I am thinking maybe it has to do with my iphone port as the prior owner had a hook up installed to the radio which allows me to connect my iphone and play music. Any suggestions? Please help.

[harborman]

How old is the battery?

[MPDano]

If you think that the iPhone connection is drawing, then remove it and monitor for a few days. Or find another mechanic for electrical issues. Seriously, find an auto electrical mechanic that specializes in this. I'm not an electrical genius so I couldn't really help you on this one but I am sure were all interested in what you might find to be you issue. Sometimes Alan (electrical guru) will chime in once in awhile, he may have some suggestions.

Have you gone through all your grounds and cleaned them? It kinda sounds like it happens when you actually "drive" the car, rather than when the mechanic just let's it sit, then starts it. It may not be charging the battery and your actually draining it by driving it. Just a thought.

[harborman]

Iphone charge should not cause this. Put an amp meter between the hot lead and battery terminal. With everything off, what does it read? Make sure all doors are closed, no lights on. Again, how old is the battery. You could have a bad cell. Make sure it is not your battery and take it from there.

[eyal928]

The battery is new and it checks out, no problem with the battery or the alternator. When the doors are closed and the alarm is activated, the amp meter spikes up to .5 momentarily but then it drops down to .05 and stays steady. And it does seem like this occurs after driving. For instance, I started the car up Saturday, drove it several times and then parked it. Tried to start on Sunday morning and I got a clicking sound and the engine wouldn't turn over. I had to jump start the car. It is driving again today, I did not hook up my iphone today and I will see if I have the same problem tomorrow morning. Anyone else have any ideas? Do I need to replace the electrical wires because of old age?

[MPDano]

I guess what I meant to disconnect the iPod stuff is to disconnect the whole system (stereo).

Anyways, chasing electrical issues is no fun and this is why I suggested a 2nd opinion using an Auto Electrical Mechanic. Also, a lot if issues can also be attributed to the engine wiring harness. I rebuilt mine on the 81 Euro, insulation basically crumbled. Look for cracks in the harness where water could have seeped through and started the corrosion process.

[aluminum]

Start Simple :
with the Battery ok ( charged ) disconnect it and let the car sit say 4 or so days > hook up the Battery and try it > If Its Hot and works fine then you have a Short > Simple yes ? well yes and no
So Now you must disconnect things until you find whats drawing power . No doubt something is drawing power if the battery go's dead
What to Disconnect ? I would start with the Alternator and The Brain
You need to buy a few tools to check for the short and such OR Pay someone
Porsche's are a Electronic Nightmare > many people sell them just because of that Issue

[harborman]

Originally Posted by aluminum

Start Simple :
with the Battery ok ( charged ) disconnect it and let the car sit say 4 or so days > hook up the Battery and try it > If Its Hot and works fine then you have a Short > Simple yes ? well yes and no
So Now you must disconnect things until you find whats drawing power . No doubt something is drawing power if the battery go's dead
What to Disconnect ? I would start with the Alternator and The Brain
You need to buy a few tools to check for the short and such OR Pay someone
Porsche's are a Electronic Nightmare > many people sell them just because of that Issue

Good ideas to start with! .05 amps is not much but I don't know what the normal draw is when off. You do have some things on as radio, clock and maybe alarm system. Maybe pull the alarm fuse first. Do as aluminum suggests first.

[eyal928]

What I had been doing is disconnecting the battery after turning the car off and it would work each time I reconnected it. I will try what you recommend. I cannot wait to resolve this issue. Love my car but this is becoming a real pain in the ass. Anyone know of a good car electrical expert on Long Island or nearby?

[harborman]

Originally Posted by eyal928

What I had been doing is disconnecting the battery after turning the car off and it would work each time I reconnected it. I will try what you recommend. I cannot wait to resolve this issue. Love my car but this is becoming a real pain in the ass. Anyone know of a good car electrical expert on Long Island or nearby?

If you can, put your amp meter back in. With car off you said it spiked to .5 amp then down to .05 amp and remained there. I would look at the fuse chart and pull the fuses on what circuits might be active with the car in off position. You will have to tape the door switch off as you need to get in that passenger side. See if you can find which one(s) drops the current drain. Any mechanic is probably going to try the same thing.

Your battery should read about 12.56 volts when charged. Try these simple things mentioned. Don't give up so easy, maybe save yourself some expense. Others may help you here as well. Good luck.

[Yoni_d]

You have mentioned that you have an alarm system. This was the problem in my case. Sometimes old alarm system doesnt switch to idle mode after activation so it can drain battery power. If you have automatic window closing mechanism that is activated by the alarm - it can also be the case.
As a first step, dont disconnect it completely - just dont activate it for a few days. if it wont help, disconnect it completely for a few days.

[Alan in AZ]

There are several things on the car that are designed to stay active for a while after the power goes off - or can even stay on if there are issues: Fan controller (for after running), flap controller, interior lights, window controller, alarm, aftermarket radios.

Make sure everything is working as expected - esp interior lights, fan controller and windows. if the wiondows work with the ignition off and doors open you have an issue, if the switched interior lights don't work you have an issue that needs to be fixed. Does your alarm actually work correctly - test it.

Alan

[eyal928]

So I have great news, the Mighty Murph of Porsche Spoke Here in West Babylon New York found the problem. It was the car alarm after all. The car alarm was hooked up to circuit number 24, the interior lights, along with the radio. Murph does not understand why they would hook up both the alarm and the radio to that circuit but he figured it out in less than one hour where the past three mechanics I used couldn't figure it out for 4 months. It pays to have a good mechanic.

So now I must find someone on Long Island who can install a better alarm and rewire the radio because it is slightly draining the battery, but not bad enough to drain it completely. Job well done Murph, thanks everyone for your assistance. I am glad this ordeal is over. Now I can enjoy my favorite car.