[Pams968]

On 10/8/19 my '94 968 tried to escape the garage - car was in reverse w/ e-brake on.  Did considerable damage to car and house.  After being diagnosed at Mayo Performance (DFW area), the following was found (in addition to the below, later discovered the incident burned out the starter as well):

 

"Attached are a few photos of the cause of all the trouble.  The first three photos show the starter, starter connections and the main harness properly secured, bracketed and routed to the starter.  Nothing externally visible or obviously damaged.  The last few photos show the jacket cut away, revealing failed insulation on the two wires that were sheathed in the same jacket.  The larger wire is the main cable that delivers power from the alternator to the starter lug, where the main battery cable is connected, which then feeds power back to the positive battery terminal.  The smaller wire in this harness is the solenoid power wire that comes from the ignition switch.  It provides power to the solenoid when the key is turned to the spring loaded start position.  Any time the solenoid wire is connected to battery positive feed, the starter will engage, and remain engaged and cranking until this connection is interrupted or the battery gives out.  These wires, a battery positive and the starter solenoid power, clearly contacted one another due to the failed insulation.  The problem has been brewing and must have finally reached the tipping point. 
 
     I must say in 33 years of working on all models Porsches, the 944/968 line in particular, I have never seen failed insulation like this.  One contributing factor is likely the fact that the jacket surrounding the wires was full of water!  These harnesses were set up exactly as per the factory layout, even though the starter was clearly replaced, properly, at some point in the past.  I am looking over the factory information we have to see if there was ever a recall, or Technical Service Bulletin (TSB), concerning this harness.  The harness itself is no longer available from Porsche, but we have the materials needed to fabricate a new harness for the wires concerned.  This is not a case of burned wires, so no other damage is apparent.  The issue is isolated the wires in this particular harness, in this particular location.  I do need to follow up on other concerns and will get to those today.  I just wanted to provide you with my findings at this point.   I'm thankful no one was hurt.  This spontaneous cranking issue could have occurred before now, but perhaps no one was around to hear it and the car was not in gear?  That is just speculation on my part."
 
Car was fixed at Advantage Autoworks (she's back beautiful!), and they discovered someone else this had happened to with a 968.  Same with Mayo - one parts supplier had their own horror story.  So definitely something to be aware of. 


For me, these were the symptoms that led to this:


-Battery drain, batteries were replaced almost every year the last 3 years
-Check engine light came on sporadically (3 years), seen by numerous Porsche specialists -code indicated knock sensors
-Knock sensors replaced, check engine light still came on, codes again read knock sensors
-Engine light would go off if car went above 3800 RPM
 
I know those aren't a scientific diagnosis but those are the things I noticed and though I told 3 prominent Porsche service providers (including a dealer) the issue wasn't discovered until a catastrophe occurred.
 
Just hoping to make people aware and save you some heartache (not to mention $$$).
Pam

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[ds968]

Oh, nooo ! That’s horrible ...and painful to see the photos. Very sorry to hear of what happened . But glad no one was hurt .

On a related cautionary note, my car also decided to start on its own and lunge forward without any provocation in the middle of the night , in the garage . It was left in first gear, and even though the ebrake was not on, I was very fortunate that it hit a bunch of large plastic bins in front of it which stppped it from running into the wall, and the car only traveled about 3 ft. before it stopped. Starter was the cause of this of course , but my cables / wires all the way from the starter itself to the battery connection were examined and found to be in good shape, so even in those cases some contact in the wire harness can cause problems , but the condition of what is shown in the above photo is unimaginable . Definitively a PSA for everyone to periodically check those harnesss and connections.

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[Velocity]

That's definitely one of the craziest automotive stories I've heard (and I've heard a lot over the years).   Glad to hear it didn't turn out any worse than it did.     Could of easily gone out into the street and ran into another vehicle if the timing was bad.   

 

Worrisome that similar issue happened to ds968.   How WOULD one "inspect" the harness for something leading up to this - sounds like the insulation was worn off inside the harness, so not sure a visual inspection even at the exact place of the worn insulation would turn up anything....?      

 

Was the motion of the car purely due to the starter engaging with the car in gear?  In other words, it never fully "started"?   ...or if so, stalled out before it went further?

 

I've normally left my manual transmission cars with parking brake ON and in neutral when parked.     Guessing that would of helped avoid damage in these cases, but wonder if starter would get burned out in this scenario?   

 

Scary......

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[ds968]

Good point, no idea how a visual inspection could accomplish much if the deterioration is internal, perhaps only telling if the insulation looks somewhat shabby , but mine didn’t . The damage to mine was limited to a smal bend in the “ German style “ license plate .

I have an very old post on this forum describing that incident, and I vaguely recall at least one other member, if not two had the identical thing happen to them, although I think in both cases also the car was not close enough to anything to cause damage or collateral damage . Maybe none travel all that far , but even the intifal lunge is strong enough ( evidently ) to take out the garage door !

Scary.

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[Pams968]

Per the shop, there's no way a visual inspection could tell you about the insulation, you have to cut the wire harness open.  And I don't believe that part is available anymore, my new one was fabricated.  The car WAS in reverse with e-brake on. This incident drained the battery (it was dead when I got to it) and burned out the starter.  I AM lucky it wasn't worse (and the car wasn't in 1st and headed into the house), but was still hard.  AAA is going to kill me on renewal with a $12K claim (that was just bodywork).  Believe me, I now leave the 968 and my Cayman S in neutral in the garage....  Hard to accept if car HAD been in neutral this could've been avoided :-(

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[ds968]

Since my incident I leave the car in neutral also. I left it in gear in the past because I kept reading in the forum that the spring clip on the ebrake is prone to braking ( supposedly a very common problem ) and ( also supposedly ) its a bit of a PITA to get to it without the car on jacks to fix it .


When I saw your garage door and read the post, I couldnt help but think of a really ugly would-be scenario for me - the 968 left in reverse , goes trough the garage door and both hit the Maserati , which is parked in the driveway, a ft.away from the garage door. Just the headlights are $ 8,000 . Not to mention what a bumper or hood repair would cost . My insurance company would put a contract out on me..and I dont mean a policy contract .


But from what I hear about AAA, its one of the most forgiving insurance companies around, so hoping you might have a pleasant surprise at renewal rather than a bad one. Theyre undoubtedly relieved no one was injured , thats where the big payouts are and resulting renewal coverage cancellations are not all that uncommon.

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[MCL968]

http://www.968forums.com/topic/16044-new...omsearch=1


There are a few things on here to note, that wire is one of them.

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[94SilverCab]

Anyone who hasn't replaced their harness by now, absolutely should. This is a known weak point.

 

I was fortunate enough to replace mine with the legendary "Ice Shark" cables, wish  we could find someone else to make them. Higher Connections made them for a short time, but he went completely off the grid.

 

Jay

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[Velocity]

Anyone who hasn't replaced their harness by now, absolutely should. This is a known weak point.

 

I was fortunate enough to replace mine with the legendary "Ice Shark" cables, wish  we could find someone else to make them. Higher Connections made them for a short time, but he went completely off the grid.

 

Jay

 

I guess the question then is, if an OEM replacement harness isn't available, and there isn't anyone making an aftermarket one, what would one replace it with?   ;-)

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[MCL968]

There is a link on here to a Summit Racing Equipment wire that I used from the Alternator to the Starter. It was long enough that I could run it along the fender well to get it out of the hottest part of the engine compartment. The rest of the wires are nothing special, you can just make them up with crimp connectors and heavy gauge wire. I put the wires in shrink tubing to seal them and offer some protection from abrasion. Note, the connector at the firewall is unusual and must be retained. One wire goes to the alternator, the other to the starter solenoid.

 

Use the little gear thing next to the search bar, search "Summit" and I will wager you will find the part number from an earlier post, and even some directions. .

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[pdxmike]

Obviously extremely alarming, very glad no one was hurt!

 

To clarify - we are talking about the harness from the alternator to starter, correct? 

 


   

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[Waylander]

No its number 22, as thats the starter cable

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[Velocity]

There is a link on here to a Summit Racing Equipment wire that I used from the Alternator to the Starter. It was long enough that I could run it along the fender well to get it out of the hottest part of the engine compartment. The rest of the wires are nothing special, you can just make them up with crimp connectors and heavy gauge wire. I put the wires in shrink tubing to seal them and offer some protection from abrasion. Note, the connector at the firewall is unusual and must be retained. One wire goes to the alternator, the other to the starter solenoid.

 

Use the little gear thing next to the search bar, search "Summit" and I will wager you will find the part number from an earlier post, and even some directions. .

 

Thanks!   

 

After reading thru about 4-5 threads that also mentioned the part being listed in "an earlier post" - here's the link to the thread that actually has the part listed on page 3 of thread, just to save someone some time.  ;-)

 

http://www.968forums.com/topic/12317-any...ns-lately/

 

I'll definitely add this item to the top of my "preventative maintenance" list if/when I get a 968 - especially given that the one I'm looking at now just had a new alternator installed due to "lack of charging" - mechanic note also stated "Found faulty main wire connection at alternator. Repaired wire/soldered new eyelet end on wire to get working properly."     

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[Kaj Hallstrom]

WOW!!!!!.......what a wake up call!!!...time to break an old habit  and leave the car in neutral with ebrake on. That is going to take some time to get used to.

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[pdxmike]

Waylander - I'm confused - I only see the two battery leads in separate sheaths on #22 above (part 944 612 067 03). They don't look at all like the damaged wires in the pics. 

 

MCL968's linked post above (thanks Velocity) seems to imply it is #23 that needs rebuilt or new (part 944 607 029 04). 

 

I haven't been under my car yet to look at the wiring, so apologies in advance if this is just really obvious once one is under there. 

 

Frankly this seems like a super dumb design decision from the outset. Starter solenoid and battery positive wires were designed to run next to each other, in the same insulation sheath, through the engine compartment?? Gotta say - I am not exactly impressed by Porsche's electrical engineering skill here. 

 

Wouldn't it make sense to rebuilt this harness by reinsulating the offending wires and routing them separately? OR running the Summit racing wire separately from the alternator to the starter, and just "decommissioning" that wire in the original harness? 

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[ds968]

Frankly this seems like a super dumb design decision from the outset. Starter solenoid and battery positive wires were designed to run next to each other, in the same insulation sheath, through the engine compartment?? Gotta say - I am not exactly impressed by Porsche's electrical engineering skill here. 

It was the same engineer - his name is Hans , just in case you were wondering - who also designed the ( plastic ) heater control valve to be located right above the exhaust manifold . What could possibly go wrong ?!

Incidentally, he came up with both of those ideas during Oktoberfest after returning from “ lunch “ .

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[J.Elenbaas]

Oeps, thought it was Heinrich  :wacko:

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[Waylander]

The photo does not specify LHD or RHD just an impression of a cable


As you know the battery on a LHD car is in the space between the engine bay and the windscreen, on a RHD car the battery is in the boot/trunk


So the picture is not an accurate representation just something to reference to


The RHD cable is NLA

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[pdxmike]

Took my harness out last week - finally - based on this post. Visually it was fine except for a little bit of loss of insulation at the alternator. Inside the sheath, the insulation on both cables was totally toast. 

 

The 968 harness is NLA. Thankfully the near-identical 944 harness remains available. The 944 harness is about 6 inches longer than the 968 harness but will fit without difficulty. It was just over $100 from Sunset. It's about a 20 minute job to pull - requires jacking the car and removing the metal gravel shield - and about an hour to put the new one back in. It goes without saying that one must disconnect the battery and put the car in neutral before getting under the car for this job.

 

You need a good light, some wire to fish the new cable through, and a 10 and 13mm wrench, maybe an 8mm to take the gravel shield down.  I looped the extra length of harness behind the alternator and attached it to the fender wall with some zip ties. 

 

As others have noted, the degree of deterioration on the original cables was astonishing and I would not have guessed on visual inspection that they were so far gone. Based on the "charred" appearance of the (former) insulation I am guessing they have been sparking for some time. Glad I dodged a bullet.

 

Based on recent reports, I'm going to say changing this harness should be at the highest priority for new owners, at the same level as a belt change.  

 

   

 

   

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[MCL968]

YES! That's what we have been saying for years. Good to know that the 944 harness will work. It never occurred to me to even check that. Thanks for the update and the information. You most certainly dodged a bullet.

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