Post 1 of 6
Turns out there are a few folks that want to see this. This started as a tangent to the "Which Engine is best, 3.2 or 3.6L?" thread. There is a voluntary factory recall on many of the 1995 and 1996 3.6L engine wiring harness' because of a bad formulation in the insulation. It turns into a crusty mess and can cause all kinds of issues.

In my case it was very bad missing when it rained and an increasingly bad idle. But in some cases folks have fried their alternators. If you had/have a new 993 then Porsche would have notified you based on your VIN, but in my case I just bought an engine so was never notified.

Here's the culprit.

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Here's what happens at the alternator
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#2

An injector branch... no wonder it was missing when it rained!
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Here's the capacitor lead... talk about a major short if it had failed.
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#3

Here's the main trunk. Lot's of ugliness in this cluster.
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First, removing all of the stock 993 wires I don't need in my harness. Otherwise there would be German spaghetti all over my engine bay!
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#4
Assuming the position...
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Finding out I have to open the access hole to get the fan far enough forward to reach the lower alternator wire (ground).
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#5

Don't even have to loosen the belt, just tilt it forward and back again after the new alternator wires are fastened, and yes. I see the leaky crankshaft oil seal issue!
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Back together and threading the wires back to the starter and reverse-light switch on the transaxle.
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#6
Now, to tidy up and look for any unattached... stuff.
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All went well and thanks again Andy for letting me know about the recall, and JT914-6 for the pix.

I've done bunches of those recalls. Good stuff. Warranty pays something like five hours.

Merc Benz from 1993-95 had exactly the same issue, but they did not recall the affected products. It was fixed from the 1996 model yers going forward, I am told.

I heard that Merc had stiffed their customers with this problem. That's a shame since there is no way to avoid replacing these harnesses on the effected cars. That would be the last Merc I ever bought.

Very interesting..thank you for the education.

Late 70s through early 90s Volvos had this problem, mostly 240s, but many 740s, too. Many 280Zs. MB has stiffed their customers on it, and Volvo, too, but the cars involved took a lot longer to have issues. Even worse is the tranny harness wicking ATF into the TCU on several MB models. Or the electric thermostat leaking and coolant wicking into the ECU on a number of BMW models. Both of the latter are major bucks.

The Cap'n

I had a '93 MB 300E, mine was beginning to have trouble and I was informed of the wiring harness problem. Got rid of the car but hated doing so as I loved the way it drove and ran. Was my second MB but most likely my last, who knows.

Perry,
BTDT with mine. It raised it's ugly almost from the minute I started my car for the first time after it was road worthy.

When I tracked down the misfire I damned near set the car on fire when the Alternator wire ground out.
It was a great thing I had more than 1 battery quick disconnect switches installed on the teener.

replacing the factory harness was a snap, and I actually ended up with an extra one if anyone needs one.

you'll sleep easier now that the old harness is in the trash.

Ron