Francois Posted 6September, 2017 Report Share Posted 6September, 2017 (edited) Hi all,I seem to have the symptoms of a bad alternator-battery cable. Seems to be a recurring problem on 997...Typical consequences are a slow crank getting worse when hot.It's not that bad, but it clearly doesn't sound good and if it gets worse over time, then I'll start having issues to start.According to what I read, the culprit is the cable harness connecting the battery to the alternator and starter motor.It's a $100ish part, but needs a lot of labour i.e. removing air-box, throttle-box, plenum, AOS tubes, etc...My battery voltage upon idle is approx 13.7V, which seems to be low - any opinions here? What is your battery voltage on idle?Any one experience this problem?Thanks! Edited 6September, 2017 by Frenchy987 Quote Link to comment Share on other sites More sharing options...
Jim45 Posted 6September, 2017 Report Share Posted 6September, 2017 (edited) Hi Mate,Had a similar issue with my 2004 996, where it would get progressively more difficult to start after multiple stop starts.No codes being thrown but found a crank angle sensor error in memory. Replaced it and the battery at the same time and it has almost entirely eliminated the issue. I can still reproduce the slow start but I have to stop start about 6 times in a row to induce it. Car never actually fails to start though.I usually run around 14v - thought that was normal.Cheers - Jim. Edited 6September, 2017 by Jim45 Francois 1 Quote Link to comment Share on other sites More sharing options...
Pauly Posted 6September, 2017 Report Share Posted 6September, 2017 I had something similar on my 944 turbo. Replaced the starter, alternator regulator and battery in that order. Replacing the old starter felt like it helped as the brushes where worn but the issue came back. put a new regulator in and still the same. Put a new battery in and the issue went away. Francois 1 Quote Link to comment Share on other sites More sharing options...
P-Kay Posted 6September, 2017 Report Share Posted 6September, 2017 Had the same issue with my 996. Once the engine was warm, say a 20 odd minute drive, stop to grab a coffee and hop back in to be greeted with a slow to no crank. Replaced the starter and cable you mention and everything was working as expected. I changed both as I didn't want to pull everything apart twice.I did this a a DIY, so it is doable, but your research is accurate with what is needed to be removed. Good Luck! Francois 1 Quote Link to comment Share on other sites More sharing options...
ANF Posted 6September, 2017 Report Share Posted 6September, 2017 First thing I would do is give the battery a full charge overnight and then see how you go. With a few shortish drives the battery will not be fully charging (batteries don't like short trips). Also take the car to one of the battery places and get them to test it (load test and the like).It may just need a good charge or be on the way out. Redracn and Francois 2 Quote Link to comment Share on other sites More sharing options...
SammyD Posted 7September, 2017 Report Share Posted 7September, 2017 The A/S cable was the first thing I replaced when I bought my 997.1 S. Replaced with the updated 997.2 cable. Very common problem and talked about a lot on many other Porsche Forums. Daz987, JB and Francois 1 2 Quote Link to comment Share on other sites More sharing options...
Francois Posted 7September, 2017 Author Report Share Posted 7September, 2017 The A/S cable was the first thing I replaced when I bought my 997.1 S. Replaced with the updated 997.2 cable. Very common problem and talked about a lot on many other Porsche Forums.Thanks Sammy - did you DIY? Or have it serviced? Any idea how much they charged you for that? First thing I would do is give the battery a full charge overnight and then see how you go. With a few shortish drives the battery will not be fully charging (batteries don't like short trips). Also take the car to one of the battery places and get them to test it (load test and the like).It may just need a good charge or be on the way out.Talked to a mechanic at NINEAUTO (P specialist) and apparently my charge voltage of about 13.7 V on idle is nominal.12.2 V on the battery is also normal albeit a bit low.I'm gonna get it tested before I go any further. Quote Link to comment Share on other sites More sharing options...
quasio Posted 7September, 2017 Report Share Posted 7September, 2017 just another data point for a 996 - I had a slow starter as well as a loud screeching noise occaisionally after start ( the bendix gear thing wasn't working 100% of the time)Replaced the starter - didn't bother with the cable (just wire brushed the connections) and it was fine after. New starter motor is super fast, and no issues starting each and every time now. Francois 1 Quote Link to comment Share on other sites More sharing options...
Raven Posted 7September, 2017 Report Share Posted 7September, 2017 My 06 997 S sometimes does this ....slow cranking when its hot generally summer weather ,,,short 5 minute trip say to the servo to fill her up can result in a slow cranking starter ....at the moment the problem is not constant ,,ie it may happen a couple of times a year ,,,I do keep my car on a trickle charger to keep the battery at full voltage ...but still have had this issue from time to time the engine does always fires up ..................if the problem becomes more constant I will look at doing the cable upgrade for the moment I can live with it ....... . Francois 1 Quote Link to comment Share on other sites More sharing options...
ANF Posted 7September, 2017 Report Share Posted 7September, 2017 Unless the cable is too small I cannot see how it would be the issue, the short trips would be."Easy" way to check, test the output voltage at the alternator and the battery, if there is a noticeable diff then it could be the cable. As I said short trips is not good for the battery and modern cars are very electricity hungry with all their features, sensors/ computers. Quote Link to comment Share on other sites More sharing options...
Francois Posted 7September, 2017 Author Report Share Posted 7September, 2017 Unless the cable is too small I cannot see how it would be the issue, the short trips would be."Easy" way to check, test the output voltage at the alternator and the battery, if there is a noticeable diff then it could be the cable. As I said short trips is not good for the battery and modern cars are very electricity hungry with all their features, sensors/ computers.Adam, there is a known issue on 997 and maybe 996 that the crimped connector on that A/S cable gets a bit loose and corroded with time, causing a higher electric resistance. Resistance rises with temperature, which explains why cold starts are generally OK (although they can lack a bit of authority) whereas warm starts are much longer (slower cranking).Slower warm starts generally point to a bad cable or starter motor. just another data point for a 996 - I had a slow starter as well as a loud screeching noise occaisionally after start ( the bendix gear thing wasn't working 100% of the time)Replaced the starter - didn't bother with the cable (just wire brushed the connections) and it was fine after. New starter motor is super fast, and no issues starting each and every time now. I've also noticed some screeching... so maybe my starter motor is going... Quote Link to comment Share on other sites More sharing options...
Raven Posted 7September, 2017 Report Share Posted 7September, 2017 (edited) This thread sheds some light on the issue .. https://rennlist.com/forums/997-forum/986396-997-1-c2s-hot-start-slow-crank-finally-resolved.html corrosion on current bolt Edited 7September, 2017 by Raven Quote Link to comment Share on other sites More sharing options...
Francois Posted 7September, 2017 Author Report Share Posted 7September, 2017 (edited) This thread sheds some light on the issue ..I did come across that one... Seems to be yet another cause, this one being located closer to the battery... ___________________________________________________________ Regarding the battery, I currently have a Bosch S5 575.035 with 680CCA (75AH)Enough or weak-ish? Edited 7September, 2017 by Frenchy987 Quote Link to comment Share on other sites More sharing options...
Raven Posted 7September, 2017 Report Share Posted 7September, 2017 CI did come across that one... Seems to be yet another cause, this one being located closer to the battery... ___________________________________________________________ Regarding the battery, I currently have a Bosch S5 575.035 with 680CCA (75AH)Enough or weak-ish? when i I get a chance u may have a look at that on my 997 could be a possible cause for my car Quote Link to comment Share on other sites More sharing options...
quasio Posted 12September, 2017 Report Share Posted 12September, 2017 also fyi, i bought a starter from amazon US.https://www.amazon.com/gp/product/B00H3R9DTM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1seems to work fine, fit fine on my 996, check fitment for your 997.ended up being 196AUD shipped for a new starter. Raven and Francois 2 Quote Link to comment Share on other sites More sharing options...
Raven Posted 12September, 2017 Report Share Posted 12September, 2017 That is a good thing to know cheers ,,,,,hate to think what my dealer wants for a starter Quote Link to comment Share on other sites More sharing options...
dan_189 Posted 12September, 2017 Report Share Posted 12September, 2017 I had a very similar issue with my 04' 996 - hard to start when warm/hot but would fire right up when cold. Turned out to be the starter cable from the alternator to the starter it would get heat soaked and then not be able to pass current. It was misdiagnosed as a bad starter but seeming your starter is making noises its most likely the culprit. I'd change both the cable and the starter.There is a voltage drop test you can do to check the cable i.e. check the voltage that the alternator is putting out and then compare it to what the starter is receiving. Francois 1 Quote Link to comment Share on other sites More sharing options...
Francois Posted 12September, 2017 Author Report Share Posted 12September, 2017 I had a very similar issue with my 04' 996 - hard to start when warm/hot but would fire right up when cold. Turned out to be the starter cable from the alternator to the starter it would get heat soaked and then not be able to pass current. It was misdiagnosed as a bad starter but seeming your starter is making noises its most likely the culprit. I'd change both the cable and the starter.There is a voltage drop test you can do to check the cable i.e. check the voltage that the alternator is putting out and then compare it to what the starter is receiving. Yes agree to all of that. I plan on changing out the cable and the starter, while I'm in there. Need to equip myself with a jack, jack stands, etc. first so it'll be in a few weeks' time. Quote Link to comment Share on other sites More sharing options...
Raven Posted 12September, 2017 Report Share Posted 12September, 2017 What are the starter cables generally worth .......? Quote Link to comment Share on other sites More sharing options...
dan_189 Posted 12September, 2017 Report Share Posted 12September, 2017 What are the starter cables generally worth .......?$80 or $100~ + $600 in labour but if you're replacing the starter it would be a lot less as the cable is attached to the starter but is coming out anyway. Quote Link to comment Share on other sites More sharing options...
Raven Posted 12September, 2017 Report Share Posted 12September, 2017 I would do the labour myself ,,,good on the tools and have all the gear ............I have a feeling mine is the current bolt as the issue has only happened a few times in 3 years ,,,,,will start there and work my way back to the engine ,,,process of elimination ... Quote Link to comment Share on other sites More sharing options...
dan_189 Posted 12September, 2017 Report Share Posted 12September, 2017 I had the dealership do mine, however having done more work on the engine now i'd be comfortable tackling that myself.The plenum was the most difficult part, once you pass that hurdle its relatively straight forward. Francois 1 Quote Link to comment Share on other sites More sharing options...
quasio Posted 13September, 2017 Report Share Posted 13September, 2017 yeh it's a bit daunting doing your own work at first, the secret is a super long 1/2" drive extension.http://www.supercheapauto.com.au/Product/SCA-Extension-Bar-1-2-Drive-500mm/215989This guy has been a lifesaver. A couple of good uni joints and adapters and stuff. duct tape to tape em all together so they dont get lost in your engine and it's all good. Quote Link to comment Share on other sites More sharing options...
Francois Posted 13September, 2017 Author Report Share Posted 13September, 2017 yeh it's a bit daunting doing your own work at first, the secret is a super long 1/2" drive extension.http://www.supercheapauto.com.au/Product/SCA-Extension-Bar-1-2-Drive-500mm/215989This guy has been a lifesaver. A couple of good uni joints and adapters and stuff. duct tape to tape em all together so they dont get lost in your engine and it's all good. Thanks for the advice. Yep, I did read about the need of a long adapter. Yours is much cheaper, thanks for the idea of buying it from an auto parts shop!Still need a bit of tooling (E12, E14 sockets), a breaker bar, and some ramps/chokes. And a helper maybe But pretty keen to tackle this one myself. Quote Link to comment Share on other sites More sharing options...
dan_189 Posted 13September, 2017 Report Share Posted 13September, 2017 Thanks for the advice. Yep, I did read about the need of a long adapter. Yours is much cheaper, thanks for the idea of buying it from an auto parts shop!Still need a bit of tooling (E12, E14 sockets), a breaker bar, and some ramps/chokes. And a helper maybe But pretty keen to tackle this one myself. Bunnings sell a kinchrome E-socket set and a few breaker bars too they are usually cheaper than the auto parts places on a few things. You won't need any ramps or chocks for this particular job but they are handy to have for future ones. Raven and Francois 2 Quote Link to comment Share on other sites More sharing options...
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