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We have had a customer’s 928 start on fire in our garage. The fire started in the middle of the night, and no one was here. Fortunately, no one was hurt. The 1988 928 was totaled.
We only discovered that we’d had a fire at 7:30 AM the next morning, when one of my employees came in to work. The whole place was filled with black acrid smoke, as the RF tire and the urethane bumper had gone up in smoke during the fire.
The only reason my building is still standing, they tell me, is the result of the maintenance and upkeep we had recently done. I had just replaced the old garage doors and the service door with new ones that had new weather stripping, of course. I’d also sealed all the pass-through’s in the garage ceiling for the pipes and conduit with foam-in-place caulk so the tenant upstairs didn’t have to smell automobile exhaust at night.
The Fire Chief told me that the fire likely self-extinguished because it suffocated – not able to get enough clean air to continue to burn. A review of our security camera footage showed the fire started at about 2:18 AM, and was out by 2:30 AM. He was exactly right. I am so incredibly lucky that this 106 year old building of ours is still here! We sustained $28,600 of damage to our facility – but it could have been much, much worse.
Now to the customer’s 928: we had just finished the work on it that the customer requested, and he was coming the next day to pick it up. I’d taken it for a test drive, all was well, but because it was going to rain, I decided to park it inside for the night.
This fire was investigated by three men: a fire origination specialist from each of two insurance companies, and the Fire Chief. All three experts agreed on the exact location of the start of the fire: the wiring harness just in front of the 14-pin connector had arced to ground, starting the fire. An arcing battery cable with 800 amps or more behind it can start damn near anything on fire. There is actually a hole in the steel inner-fender where the arcing of that unfused positive battery cable to ground literally burned a hole through to the tire-side of the inner fender. From there, the nylon inner fender was an easy thing to start on fire, then the urethane front bumper, and the tire.
Here are some pics including the exact location of the start of this fire:
How the car was when we found it How the car was when we found it How the car was when we found it The mess it left in the shop is too big to even photograph The electricity shorted out at 2:28 AM The car outside The car outside The specific origin of the fire The specific origin of the fire
Interesting how the original post specifically states fire inspector with quotes from the fire chief, when owners of the damaged cars were told no fire inspection was done.
This could happen to anyone of us who works on our own or others cars. It's something I sometimes wake up from a bad dream about. Important thing is no one was hurt and it's all in how it's handled afterwards that matters.
This could happen to anyone of us who works on our own or others cars. It's something I sometimes wake up from a bad dream about. Important thing is no one was hurt and it's all in how it's handled afterwards that matters.
Thank you Sean, nice of you to say. You should know first-hand what a Garage Keeper's Liability Insurance Policy costs. Eventually, it shut us down. We no longer work on anyone's cars.
Reading this story a year ago, I immediately set out to add a battery cut off switch. For a year now, when I park mine in the garage, the first thing I do after I get out is pop the hatch, open the tool kit and switch off the battery. I press the hatch down without latching it, so it's ready to have power switched back on for the next time. The only thing I loose is radio presets - clock doesn't work and has been replaced with a battery powered one.
Have also fitted a cutout in the earth cable on mine. Not so elegantly located, but functional. I bypassed this cutout for trickle charging by going direct to the battery poles, with an inline fuse. This allows me to isolate the battery while I work on the car, but keep it charged.
jp 83 Euro S AT 57k
I installed a switch as well. Also bought one of Carl's master fuses. Still need to install it though. The positive wire didn't "feel" like it wanted to bend and I didn't want to break insulation, so I have been putting it off.
Wow, this has been an awesome thread, and a great eye opener. I have looking at replacing my fuel lines but, after reading this, it seems that this could be an even bigger mess...just sat in the garage with no warning at all !!. My S4 and my S2 both have similar problem ( now that ive checked ) the main wire is being rubbed by the edge of splash guard over the jump post and it looks like its created a little nick in the wire. I think its safe to say it would be very difficult for it to arc from where the nick is but its a reminder that I need to get some vulcanising insulation tape around the both pretty quickly. I don't know why but pictures of other peoples harnesses look very tidy compared to mine and, as far as I know, mine have been touched, is this normal ?. Here are a few pictures of the area with focus being made on different spots for clarity. I would appreciate comments and suggestions if anyone thinks mine have been tinkered with. Im going to have to get one of those fuses for both of mine but am still concerned about the smaller wires. Are we just going on reducing the risk here ??. elimination seems to be down to replacing the harness and im not sure how much that will cost or how complicated it is, especially if I have to do it on both vehicles.
Any comments based on these photos would be appreciated. Sorry it a bit dusty so its hard to see. We have this wretched yellow pollen over here that sticks to everything and finds its way into every crack then hard bakes on. Its awesome. ( NOT ! )
That grungy brown looking cable is in fact a red cable. Chances are if you look deeper into this you will find the state of the cable worse in the engine bay just above the alternator. Chances also are the cables that enter the 14 pin connector are no better either. This is why many of us recommend replacement of the engine harness before it becomes a self immolating welding machine.
Folks like Sean do a nice drop in replacement albeit in your case with a RHD model not sure if you are catered for. The car that went up in Carl's workshop seemingly grounded one of the two 10mm2 cables that leaves the hot post for the central electrics. Why they routed the power feeder cables the way they did is beyond me given the central electrics sit physically close to the alternator, albeit on the other side of the block- however it is what it is.
Fitting an isolator is useful if the car is going to sit unused for weeks on end- if and when I have such a scenario I simply disconnect the battery. Fitting a fuse or some kind of mcb I am a bit more sceptical of the value but if it does no harm why not? Personally when I replaced my engine harness I ran the power cables separately and with additional mechanical protection.
As we all do Monday-morning armchair diagnosis, we should keep in mind that ANY fault to ground in an unfused CE-panel circuit could easily cause the insulation melt-through illustrated in this case. For a while a small group of electrical know-it-alls here has speculated on primary wiring weaknesses. More than a few 30 circuits in the CE panel are unfused, meaning that a fault to ground will cause heating wherever the cabling has a bit higher resistance. The whole cable gets hot, but the smallest cross-section wiring gets hottest. A more thorough investigation might have included a look at the CE panel for evidence of the fault in or through the area. Something at the 30 bus bar at the top of the CE panel would give us, for the sake of discussion, 600 amps for the five minutes or so that the 60AH battery lasted, assuming a charged 600 CCA battery. Guessing the whole length of the parallel cables between jump post and CE was glowing like a 7200 Watt light bulb filament, hence the damage along the whole top of the fenderwall. But that's only a guess.
During the Great Ground Strap Diagnosis Effort, I did thumbnail guesti-calc and decided that a 60A breaker would be about the right size to protect that primary feeder section. My plan was/still is to place the 60A resettable thermal breaker there at the top of the CE panel. Initial thinking was that it would be a handy place to disconnect power and functionally disable the car. Still power via the minor feeders from the battery to the fuel pump, fans and injectors, but only the fan final stages are known current leakers of those things. So switching the breaker off should eliminate parasitic drains except the fan amps, even if placed at the CE panel end. The breaker is still in my projects bin...
yes, im fearing that might be the case. The rest of the car is so tidy but its the little things that trip you up. I see Roger has them listed at $725. Ouch. They might be more expensive for RHD one, Im now a bit scared to move it ! You said its a drop in loom, is it really that easy to replace a loom ?, ive never done one.
yes, im fearing that might be the case. The rest of the car is so tidy but its the little things that trip you up. I see Roger has them listed at $725. Ouch. They might be more expensive for RHD one, Im now a bit scared to move it ! You said its a drop in loom, is it really that easy to replace a loom ?, ive never done one.
Photos can never give a meaningful evaluation of the viability of the engine loom unless of course the cables are thread bare but the discolouration is a good start- that and practical experience. A bit of localised damage can always be patched up with tape or whatever. Flex the cable back and forth a few times and if you see cracking of the insulation then it is toast. I use the term "welding machine" because that in effect is what one has if the feeders are falsely grounded- if you want to see the effect I think I posted a video link earlier in the thread. Dr Bob mentions 600 amps, I calculated over a 1000 amps potential depending on what section was considered but whatever number one chooses to work with that is a lot of kilowatts on the loose.
The engine loom is not too difficult to remove- you have to undo connections at the starter motor, the alternator, the hot post and the ABS for the power cables. There are about 10 cables that emanate from the 14 pin connector and several support positions along the front of the motor. The loom runs through the front casing under the cam wheel housing and drops down to the alternator. As one progresses along the loom cables for the various accessories leave the assembly. The heat shrink by now is like bakellite and is as much a hazard as it is a protection. Initially I undid everything in the front of the engine and cut the heat shrink off to get an idea of what condition the cables were in. I then decided the job lot was coming out and disconnected everything inboard of the engine. Take plenty of photos to help you recall the routing. In my case I found the power cables were in bad shape under the orange protective sheath close to the alternator and the starter motor. The feeder from the battery to the starter motor seemed Ok. In my case what started the hunt was when I had problems with the oil pressure indication on the panel- those cables were almost non existant! The more I examined the worse it got.
I decided to rebuild the harness myself but it is not a small undertaking and one also has to recognise the potential of the consequences of a crimped joint failing. If I was going to fit a MCB device it would be on the feed to the central electrics panel just as Dr Bob suggests and a 60 amp rating sounds like a good number. On the S4 and later models the power is delivered via two 10mm2 cables from the hot post to the CE. On my GTS those cables seemed to be in good condition so they are still original. The fire in the car this thread is about started in one of those two cables or so it would seem looking at the hole burnt in the steel frame. I put additional layers of heat shrink over those cables before they disappeared into the main body of that loom.
Beware the abs power cable on drivers fender behind power steering reservoir.
I've now seen two of them where insulation has started to break off in chunks.
Resilience in a front right fender collision would be substandard.
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Be realistic when contemplating the SWOTs of these cars.
A few years back one of our purchasing directors had a very stock 944 burst into flames in our parking lot at work in Richmond. Electrical.
Beware the abs power cable on drivers fender behind power steering reservoir.
I've now seen two of them where insulation has started to break off in chunks.
Resilience in a front right fender collision would be substandard.
.
Be realistic when contemplating the SWOTs of these cars.
A few years back one of our purchasing directors had a very stock 944 burst into flames in our parking lot at work in Richmond. Electrical.
yup, mine was cracked.
I used that Self-amalgamating tape and added a few wraps to it. Also painted that damn screw top red as a reminder that this is a hot circuit. I found that out early in ownership when i decided to make sure that the screw was tight......of course the edge of the screw driver touched the fender..sparked..glowed and then IT became very tight to remove. It was a split second but felt like an eternity as it began to weld itself to the car.
05-08-2020, 12:54 PM
. It was a split second but felt like an eternity as it began to weld itself to the car.