Battery will not hold charge fix- time will tell- w/pics
#1
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Join Date: Mar 2004
Location: Phoenix and Forest Virginia
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Recently got a request to help out troubleshooting a battery will not hold charge issue. Since I had stuff to use for troubleshooting I was happy to help out. Turns out I had this problem in my parts cab when she was running so it was a chance to learn something also.
A fellow lister needed a harness in good condition to see if this could be the culprit. The start and charge wiring consists of 2 harnesses linking the battery, the alternator and the chassis harness.
These can be found used but they are no longer manufactured new.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13878-968-start-charge-wiring.jpg)
Part 23 runs from the starter to the Alt to the chassis harness on the fire wall buried under the wire cover deep behind the brake booster.
Used it sells for - hold your seat- $180...wow. Part 22 runs from the bat to the starter and ground etc.. It sells for $160 to 180 used. Hard to believe.
If you can find them new I remember the prices being about half the above but I could not find any in stock. If they are out there please post. I measure the cables and have the info to make them new if I can locate the last connector in the fire wall. I am looking and am rather confident I can make one. If anyone has this problem and cannot find a new or used one, let me know, I should be able to make one for you.-- anyway
For part #s the tip and manual parts are different. #22
944.612.027.03 Wiring harness battery starter /LL
944.612.027.04 TIPTRONIC Wiring harness battery starter /LL
#23
944.607.029.04 Wiring harness starter generator
944.607.029.08 TIPTRONIC Wiring harness starter generator
Although they are different parts the only difference is length. The tip seems longer but both work. I pulled one out of the cab which was not holding an charge (or not charging properly) and found it brittle, fried, and having higher resistance than a perfect one pulled off another car I have. - If you have never had major service these things are in there- the wire managment system of a car never molested is amazing. It was bolted, hooped and screwed down everywhere. In typical Porsche fashion.
So- if you find one either tip or manual will work. Pics of the good vs. bad. The positive was brittle and melted the covering off the lead on the alternator and at the chassis, the starter was not so bad. I would of never guessed until I got the wire out of the car. The burnt one would not hold a charge- most likely not properlly charging and prematurely killing batteries. The nice one worked as designed.
Check your #23 wire if you are having problems. may be the real problem if your battery is not charging or holding a charge properly...
Cheers, Mike
Pics of good vs bad and the chassis connector location.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13880-alt-wiring-004.jpg)
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13884-alt-wiring-003.jpg)
White connector in behind the brake booster
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13881-alt-wiring-007.jpg)
The one on the left is the good one- note the sheathing missing and dry rotted off the one on the right which was the bad one.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13882-alt-wiring-006.jpg)
Good top - bad bottom
A fellow lister needed a harness in good condition to see if this could be the culprit. The start and charge wiring consists of 2 harnesses linking the battery, the alternator and the chassis harness.
These can be found used but they are no longer manufactured new.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13878-968-start-charge-wiring.jpg)
Part 23 runs from the starter to the Alt to the chassis harness on the fire wall buried under the wire cover deep behind the brake booster.
Used it sells for - hold your seat- $180...wow. Part 22 runs from the bat to the starter and ground etc.. It sells for $160 to 180 used. Hard to believe.
If you can find them new I remember the prices being about half the above but I could not find any in stock. If they are out there please post. I measure the cables and have the info to make them new if I can locate the last connector in the fire wall. I am looking and am rather confident I can make one. If anyone has this problem and cannot find a new or used one, let me know, I should be able to make one for you.-- anyway
For part #s the tip and manual parts are different. #22
944.612.027.03 Wiring harness battery starter /LL
944.612.027.04 TIPTRONIC Wiring harness battery starter /LL
#23
944.607.029.04 Wiring harness starter generator
944.607.029.08 TIPTRONIC Wiring harness starter generator
Although they are different parts the only difference is length. The tip seems longer but both work. I pulled one out of the cab which was not holding an charge (or not charging properly) and found it brittle, fried, and having higher resistance than a perfect one pulled off another car I have. - If you have never had major service these things are in there- the wire managment system of a car never molested is amazing. It was bolted, hooped and screwed down everywhere. In typical Porsche fashion.
So- if you find one either tip or manual will work. Pics of the good vs. bad. The positive was brittle and melted the covering off the lead on the alternator and at the chassis, the starter was not so bad. I would of never guessed until I got the wire out of the car. The burnt one would not hold a charge- most likely not properlly charging and prematurely killing batteries. The nice one worked as designed.
Check your #23 wire if you are having problems. may be the real problem if your battery is not charging or holding a charge properly...
Cheers, Mike
Pics of good vs bad and the chassis connector location.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13880-alt-wiring-004.jpg)
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13884-alt-wiring-003.jpg)
White connector in behind the brake booster
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13881-alt-wiring-007.jpg)
The one on the left is the good one- note the sheathing missing and dry rotted off the one on the right which was the bad one.
![](https://rennlist.com/forums/members/notthd-albums-start-and-charge-wiring-picture13882-alt-wiring-006.jpg)
Good top - bad bottom
#2
Rennlist Member
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I am the person who needed #23. I always had a feeling it was a corroded cable. The place of the alternator pin for this cable is right below the throttle body. Our throttle bodies run coolant to wam them for emission purposes.
If the O'ring gasket fails or if you get a coolant leak on your throttle body, chances are, coolant will drip on #23 and eventually cause corrosion.
Mike was very helpful in getting me a replacement.
Symptoms for a bad cable are low voltage and voltage drop when you put accessories on. Thanks to Mike, I show a full 13 volts at all times now.
It did end up eating my battery prematurely. Fortunately I have an Interstate and they gave me a brand new replacement, free of charge.
Regards.
Raj
If the O'ring gasket fails or if you get a coolant leak on your throttle body, chances are, coolant will drip on #23 and eventually cause corrosion.
Mike was very helpful in getting me a replacement.
Symptoms for a bad cable are low voltage and voltage drop when you put accessories on. Thanks to Mike, I show a full 13 volts at all times now.
It did end up eating my battery prematurely. Fortunately I have an Interstate and they gave me a brand new replacement, free of charge.
Regards.
Raj