user 72902

I replaced my battery/starter cable on a 2005 997.1 but unfortunately my camera malfunctioned so my pictures are not available. There are pictures at www.RennTech.org (go to 997.1 common fixes /repairs) but I did not follow those instructions that closely.

See diagram below.

The cable is part # 14 for reference below. You can see where it ties into the alternator and starter, however, the starter is oriented 180 degrees in the opposite direction.


The tools you will need are ordinary mechanics tools of assorted 3/8 & ¼ metric sockets and wrenches, and extensions. In addition you will need female torx E-12, E14, and E16; male T-20 for under belly pan removal. I’d recommend a limited access ratchet set but not required. Also have a little Pentosin power steering fluid to top off your reservoir.

1. My car was on a lift so I removed the most rear under belly pan (4 x T20 torx) and set aside. For under the car you can see part 15 which is the end of the cable on the passenger side of the transmission and the two bolts (16) holding the solid plastic clamp.

2. Lower car and remove negative battery connection and cover with a towel as well as place a towel between the hoof and latching mechanism just in case it decided to lock while the battery is disconnected.

3. First thing to do at the rear of the car is place a blanket over the rear bumper and I always wear sweat pants – no belt or anything that could damage the exterior of the car while working.

4. Step 1 - Remove the Air Filter Box. There are no screws or bolts. Just squeeze the connector and pull out and open the two clamps that hold the connector wire. Pull out and set aside. I did not remove my engine hood and it did not cause any obstruction while performing this job. I do not recommend removing it.

5. Step 2 - Remove Serpentine Belt. I first marked the direction of travel so I could install in the same direction. I’m not sure if it mattes but like most Porsche owners I’m a little process oriented. Ok I’m **** retentive. Use a 24mm socket on a breaker bar on Tensioning Pulley and rotate releasing the tension and remove.

6. Step 3 – Remove Throttle Body and Plenum. Use E12 torx to remove the 4 bolts disconnect the connecter plug with a squeeze. I keep a bag of sealable sandwich bags to put each component’s bolts and removed parts into keeping things organized and making sure the same parts go back together correctly during reassembly. There are a lot of parts coming off for this procedure so you need to be organized. Use a 7mm socket and loosen the 4 (two one each side) hose clamps and wiggle the plenum out and set aside.

7. Step 4 – Remove Power Steering Reservoir. There is a slip ring on the base that rotates about 90 degrees. It has a tab on it so you get a finger on it and rotate it counter clockwise. You will also need to remove a 10mm bolt at the top of the reservoir. At this point you can pull the reservoir out and a small amount of hydraulic fluid will spill. I had a shop rag placed below and quickly turned the reservoir which minimized any loss; a quick shot of break free took care of the mess. Stick a rag or something in the filler tube of the power steering fill to prevent any foreign objects accidentally entering.

8. Step 5 – Remove the Alternator. This was the most difficult part of the job and consumed about half of the project’s time. I’m sure someone out there could have done it much faster. Using the E16 socket remove the two bots that hold the alternator in place. One bolt simply comes out and the other holds the upper Idler Pulley. The only reason the alternator needs to come out is because I could figure out how to disconnect and reconnect the new cable because the connection is at the rear of the unit. The alternator is really packed in there and there is hardly any space to move it. Just to make sure I didn’t damage it I removed the lower Idler Pulley because it seemed a little too close to the action. After a lot of rocking back and forth the alternator was free and slid forwards allowing for a 13mm socket to remove the old starter/batter cable. If it makes it easier you can disconnect the other end of the starter/batter cable from the starter and you can pull the alternator out even further.

9. Disconnect Opposite End of Cable. Lifted the car back up and with a 10mm socket disconnected the far end of the cable from the passenger side of the transmission and the two mounts (part number 16 on diagram). Now the only thing holding the cable was two plastic clamps.

10. Remove AC Compressor. Lowered the car and could easily reach the first clamp. I opened it and pulled the cable out. The second one was not accessible without pulling the AC Compressor. There are two bolts in the front (E12) and one on the passenger rear near the top (E14). You can pull the two front ones easily and with everything else out of the way you can take your left arm and reach around and feel it and guide the E14 with extension and loosen. The bolt will not come out but pull it up and then pull the AC compressor forward. Now you have enough room to get at that rear plastic clamp. The plastic clamps slide onto a metal prong so I just pulled them up and them went under the car and removed the old starter/battery cable. I think it is very important to reinstall the cable using the clamps because it will keep the cable away from heated areas.

11. Insert New Cable. Went under the car and feed the cable along the same path as the old cable – that means you need to make a mental note of the old location. My first attempt it simply rapped over the transmission but the second try I could grab it from above and pull it into the engine bay. I went back under the car and used a 10mm socket and installed the new cable along the passenger side of the transmission and the plastic clamp (2 x 10mm bolts). That is all you can do from underneath your car besides reinstalling the belly pan.

12. Attach Cable to Alternator and Reinstall Alternator. Install the cable was a snap; one 13mm nut and you’re done. Installing the alternator was worse than removing it. I wiggled that thing what seemed like forever and that stinking oil filler tube really started to get on my nerves. There is no place to put it and it was just always in my way when working on the alternator. The fit was so tight that I used emery paper to work on the brackets to try and make it a little easier, and finally it went in. Installed lower Idler Pulley.

13. Connect Start/Battery Cable to Starter. Use a 13mm socket and attach the other end of the cable to the starter. As you have noticed by now the connection of the starter faces the rear of the car and is accessible without removing the starter. Slide the rubber boot over the connection on the starter.

14. Connect the Two Plastic Cable Clamps. Simply slide them over the metal prongs. Now the cable is 100% installed.

15. Reinstall AC Compressor. Pull the rear E14 torx bolt up and slide the compressor back into position. Insert the two front E12 bolts and then once again use you left hand to help guide the E14 rear bolt into position and align the socket. Tighten everything down.

16. Reinstall Power Steering Reservoir. If you were careful you will only need a little bit of Pentosin to top off the reservoir. This is where you will be thanking me for advising you to have this stuff before you started.

17. Reinstall Plenum and Throttle Body.

18. Reinstall Serpentine Belt.

19. Reinstall Air Filter Box.

20. Reinstall Under Belly Pan.

21. Started and drove the car. PASM warning light went on due to battery disconnect but went out in a couple of miles which is normal. Everything operated properly.

Lysoleverywhere

How long did this take you?

Recommend replacing anything else while doing this job?

Spiffyjiff

i have not done this myself - nor would i have the patience/SKILL! - but ya might as well consider (preventative) changing AOS and starter. cheap-ish parts and relatively easy swaps considering you're deep in there for the cable anyway.

user 72902

The job took me about 4 hours and half of that time had to be the removal & install of the alternator (I'm sure I was doing something wrong). AOS replacement is a good idea depending on its age.

vern1

Just reviving this for a quick question. I had the wire harness replaced by a shop and the car seems to have started smoking on start up. It has done this before but not through the winter and was wondering if there is any way the AOS could have been damaged in this job?

I don't think so as it doesn't appear that it needed to be removed but just checking before I call the shop back or concluded that its just the nature of the smoking beast (again) and the timing is just coincidental

Thanks

user 72902

You're correct that the AOS was not removed nor was it in the way.

cali_banks

I'm wondering why you can't just add a second cable between the starter and alternator, I'm would give it plenty of grounding, instead of taking the whole car apart.

vern1

Thanks. So it appears that the restart of the smoking is coincidental to the wire harness repair. I will have to look elsewhere

yvesvidal

For having changed myself the alternator cable and the starter, I can attest that there are more than a few hoses which are disconnected and re-connected (at least they should be) to the AOS body. These hoses and their couplers are very fragile (brittle plastic) and must be carefully handled to not damage them. Without touching these hoses, access to the alternator cable and starter is not practical or simply impossible.

This is all I will say on the topic. Strange coincidences sometimes happen.

Yves

Zarajohn

Hello,
Turn off the ignition and remove the negative battery cable from the battery. Remove the positive cable (the large cable that runs to the battery) from the starter. Disconnect all the bolts that hold the starter to the block, using a ratchet. Remove any other supporting brackets holding the starter in place. Remove all the bolts holding the starter. Don't force any bolts that are very tight and are difficult to remove. Rather, use a lubricant or grease to help you loosen the bolt.
Thanks
Zarajohn@

DB's997

I recently had my starter replaced, Porsche recommended that the cable from the battery to the starter be replaced as well. Porsche quoted me $1800 to do the job. I took my 2006 997 to my independent mechanic who informed me that the cable replacement was a 6 hour job. He suggested we not replace the battery cable. I called up Porsche and they told me, 6 hours was less than they thought it would take, but suggested that replacing just the starter would be OK.
So we replaced the starter and all my starting issues were fixed. Looking back now, it appears the $1800 quote from Porsche was pretty good, considering they were going to spend so much time replacing a cable that did not really need replacing. Crap! it is just money....

user 72902

I need to get a job as a Porsche mechanic.

Doug_B_928

I have completed a detailed, pic-intensive DIY write-up on this procedure. I've had a difficult time getting the attention of any moderators to get a link to the pdf so I can post it here (it's holiday season, so I understand). Renntech allows attachments over 5MB so I have posted it over there for anyone that is interested.

Ptech1

Says someone who doesn't understand dealer/"technician" labor split percentages...

Excessive starter average draw (while it is failing) is the root cause of the harness overheating and becoming damaged, in turn causing even higher amount of resistance to overcome (and obviously worse when hot).
The two are almost always mutually exclusive. Therefore replacing just one or the other is just a band aid and not typically a full solution for starting concerns, even if it takes some time for the other to finally show signs again.

user 72902

I understand the quote from the dealer below. It's a $100 part and took me 4 hours in my garage.