Electrical failure in 993

[manitobadave]

Driving my 1995 993 C4 (with 85K miles) across Canada today. Completed 500+ miles without a hitch. Then in sequence:
Radio died. Cruise control cut out as the analog speedometer under read and then went to zero. The lights in the oil pressure display came on one at a time:
Brakes, ABS, Parking light and then ??ABD.
At this point the engine died.
The immobilizer light came on and the airbag warning and the belt warning ( In the Speedometer dial)
When I tried to restart the car, the warning lights flicker and there is a clicking noise but the engine does not turn over.
The radio now works again as does the 12v cigarette lighter. The immobilizer locks the car and arms it normally.
I checked the fusebox and even replaced the DME relay but no help.
The car was towed to a VW shop and I am holed up in a hotel so any help would be gratefully received. Thanks
Dave

[Bob Kontak]

Why would the radio come back on when it was dead before? I am thinking battery failure and not running it for a while allowed it battery to kinda sorta juice itself back up a bit and allow some of the non high amp stuff to work. Clicking noise is the basis for my thoughts.

Decent hotel?

[manitobadave]

Motel 6 - mind you its cleaner than some of them
Battery Hmm. The radio has a large amplifier attached. I wonder whether it was draining the battery. Thanks

[shahram]

Did you check the fan belt and the alternator belt? How long did the engine run after the radio died?
Either the battery is not charging or not holding the charge or the alternator failed.

[dtw]

Agree w/above. Failed alternator.

[silver911rdb]

Not sure if this would have anything to do with your problems but.... the 1995 model year had a recall on the engine wiring harness. The shrouding on the wires would deteriorate and cause them to short out against each other. I had this same problem on my 1995 993 engine and all the wires were melted together when it finally went. Something to be aware of if you own a 1995 993.

[1990C4S]

My guess is that without any load your battery will power the radio. Add anything else, like a running car, and the voltage drops too low. Sounds like you weren't charging the battery while you drove. Alternator light should have come on, so I wonder if it works properly now.

Battery voltage is likely under 10 volts right now. Just a guess.

Football starts at 3 PM eastern time today. If that helps.

[herman maire]

Put a GOOD fully charged battery in and try to start it up. Report back with the results.

Its sounds like your alternator died and you slowly drained your battery. When the battery gets below a certain voltage the electronic get crazy.

[Grady Clay]

Originally Posted by silver911rdb

Not sure if this would have anything to do with your problems but.... the 1995 model year had a recall on the engine wiring harness. The shrouding on the wires would deteriorate and cause them to short out against each other. I had this same problem on my 1995 993 engine and all the wires were melted together when it finally went. Something to be aware of if you own a 1995 993.

+1

I would call PCNA today (they should be open in Canada today) and find out for sure that the engine wiring has been repaired/replaced.
That failure is truly ugly.
I suspect it could cause your sorta bizarre set of symptoms.

It is a recall issue and repaired under warranty.

Best,
Grady

[1990C4S]

Originally Posted by herman maire

Put a GOOD fully charged battery in and try to start it up. Report back with the results.

Just don't drive away until the alternator is properly tested.

Put a voltmeter on the cigarette lighter at idle.

[1990C4S]

Originally Posted by Grady Clay

I would call PCNA today (they should be open in Canada today) and find out for sure that the engine wiring has been repaired/replaced.

It's a holiday in Canada today.

And I hope it's not the harness, that will be a one week repair (or more) up here. But that is a possible cause.

[porschenut]

Did your alternator warning light never come on? Prior to the failure, did it come on whenever you turned the key to start the car? If not, then the light itself wasn't working, and therefore it failed to notify you in advance that there was a charging system issue.

If you can get the car to an auto parts store, they should have a code reader to see if there are any trouble codes pointing to the problem.

[David]

I've heard 993's have a problem with the battery cable from the battery to the starter.

[silver911rdb]

So...did you ever find out the problem?

[manitobadave]

Thanks guys.
Sorry I took so long to reply but Im still on the road (with a rented Chevy Impala !!)
Apparently the alternator is shot and is being replaced - the mechanic also talked me into a new battery - well I can see it could be defective.
Latest info is that the alternator shaft and bearings were seized. I dont quite understand this as I assumed the alternator was driven via the belt - which incidentally was fine.
From my limited knowledge of the engine I believe the fan is included in the assembly and that is driven by the shaft??.
So did the shaft seize and damage the alternator or vice versa?
I will have the recalled wiring checked and the error codes read when I can get it back to civilization - thanks for the tip.
Cheers Dave

[Lorenfb]

"Clicking noise is the basis for my thoughts."

- Bob Kontak -

Doesn't take a whole lot of thought to conclude that the battery was barely capable
of energizing the starter solenoid, the result of a dead alternator.

"So did the shaft seize and damage the alternator or vice versa?"

Very unlikely that the shaft was seized, thus damaging the alternator,
as the belts would have been damaged/broken/thrown-off. When that
occurs, the usual result is a damaged fan and alt housing. The shop
my have shifted the shaft of the alternator when removed the fan,
resulting in the shaft not turning (seized shaft?).

Most likely just worn brushes in the alternator regulator.

[midnight911]

Originally Posted by Grady Clay

+1

I would call PCNA today (they should be open in Canada today) and find out for sure that the engine wiring has been repaired/replaced.
That failure is truly ugly.
I suspect it could cause your sorta bizarre set of symptoms.

It is a recall issue and repaired under warranty.

Best,
Grady

+2...
i highly encourage you check if the harness has been replaced. before you know it, the car would start by itself and drive away. i'm not kidding.

[Lorenfb]

"i highly encourage you check if the harness has been replaced."

A simple inspection of the 993 engine harness on the left side (driver's) as it connects
to the body harness will usually reveal disintegrating insulation which requires
immediate replacement (NO REPAIRING OF THE HARNESS).