Smoke from dash - what should I inspect/replace?

[universeman]

Had a flat today. While refilling the space saver spare with the 30-year old compressor :-/ - no option at the time - I got smoke pouring from the dash. Cut battery (yay quick disconnect - may have saved the car) until smoke stopped, and limped home.

Now I have no power to the 12v cigarette lighter and no ashtray light. These of course are not critical items, but I'm worried about wiring damage and what else might happen. Any advice on how to assess the damage from anyone who's been through it?

[DRACO A5OG]

Oh snap.

You will need to remove the air intake screen, tube & fresh air components from the frunk to gain access to the cigarette lighter wire. Most likely that has burnt/melted.

The ashtray light is part of the gauge and instrument light system (black with blue wire cluster). Hopefully it is just a blown bulb. Do the gauge lights work? ( good idea to install a fuse here )

What concerns me is that the fuse did not blow first. Check to make sure the circuit for the cigarette has the correct fuse. PO may have installed too large of a fuse which would result in melting or burning of the wire. As a mater of good practice, make sure all fuses are correct sizes to avoid this type of event in the future.

Jim

P.S. did you keep the car on while you were using the pump or just battery power?

[sammyg2]

Originally Posted by universeman

Had a flat today. While refilling the space saver spare with the 30-year old compressor :-/ - no option at the time - I got smoke pouring from the dash. Cut battery (yay quick disconnect - may have saved the car) until smoke stopped, and limped home.

Now I have no power to the 12v cigarette lighter and no ashtray light. These of course are not critical items, but I'm worried about wiring damage and what else might happen. Any advice on how to assess the damage from anyone who's been through it?

Inspect the name tag on the car and make sure it doesn't say JAGUAR


Sorry, couldn't help myself.

[universeman]

Sammyg2, it's a Porsche (I just checked.) However I did just have the entire car re-wired by a British gentleman named Oliver who drives an XKE and wears tweed.

Update: the ashtray light works, as does instrument panel. The 12v outlet shows power when I use a signal light, but it's weak. I think the wire is burnt.

I couldn't keep the car running because (here's more) the handbrake lever is out of the car right now while I diagnose the brake light issue. No way to keep it running in neutral without it rolling away. (May start carrying wheel blocks.) Curious what difference it might have made?

Cigarette has a 25A fuse. As luck would have it, the super-fancy fuse panel upgrade from the UK guys who make CDI+ is on a FedEx truck on its way to my house as I type this. Will probably be installing it tonight.

[86 911 Targa]

^^^^^
Here's a few dash lights ideas.


^^^^^
The A/C evaporator.


^^^^^
And, if you don't want one of these.


^^^^^
Add one of these....

Fusing was not one of Porsche's finest hours.......At least on our 3.2.

Good luck,

Gerry

[Charles Freeborn]

Oh boy, I hope you don't have what I've been chasing for some time now....PO did a crappy alarm and stereo install and fried wiring inside one of the harnesses. It stayed hot long enough to melt through adjoining wiring. Had to cut open the harness, replace damaged wiring and re-wrap the affected areas. Still have a gremlin in there somewhere that gives goofy turn indicator lights in tach... Major PITA... Wishing you better luck than I had...
I think wiring up a dedicated 12v fused outlet in the frunk for purpose of tire inflator is a swell idea.

[universeman]

Thanks for the fuse ideas

I'm hoping I don't have gremlins from this...so far the only casualty is my 12v cigarette socket...

Goofy turn indicators in tach could be from turn signal housings not making good contact/ground - I already chased that one down in mine

[ted]

Be very careful.
You may have one short, one wire that is glowing red hot melting and smoking off the wire insulation.
After that the glowing red hot wire will melt through the insulation of any wires it touches creating a massive short and fire potential.

[simonstorey]

Originally Posted by sammyg2

Inspect the name tag on the car and make sure it doesn't say JAGUAR


Sorry, couldn't help myself.

Am I the only one that appreciates this genius comment?

[mreid]

Ancient Chinese proverb:

Only in air cooled Porsche does the wire become the fuse, the fuse become the fire, and the fire become the car.

[Crude Rudy]

When this happend to me it was the left footwell blower that smoked and I was lucky it did not go further, it was a mess when I took it out to inspect.

[dad911]

I would leave the battery disconnected until I could inspect & repair the wiring. Where there is smoke, there is burned insulation, and likely melted insulation in other circuits.

[pkabush]

My 930 used to spew smoke through my cabin vents at random times. Had the unmistakable smell of burnt electrical wiring. Really scary. I spent countless hrs looking but never found the problem. Finally, I pulled the after market alarm, stereo and all the associated wires. The wires alone filled a 5 gal. bucket. Problem solved.
It sounds like your issue is isolated to the cig. lighter but, perhaps this info will help someone else. As noted above, these cars were not wired very well from the factory. Not as bad as Jags or other Lucas wired Brit cars but poor nevertheless. Adding more electrical components to these old girls is like throwing fuel on a fire.

[timmy2]

ive just repaired 2 dash harnesses in the last month or so that had melted circuits in the clock/interior lighting as well as the lighter/fog lamp/blower motor circuits.
Those circuits are paralled up together all over the place.
On an '88 turbo harness there was even damage that was in the brake circuit.
Once there is some melting and two or more circuits get involved the damage spreads all over.

Sent from a lounge chair by the pool in Maui!

[nineball]

similar thing happened to me a few years back. turn on the ignition and the inside of the car looked like a night club - so much smoke you couldn't see. in my case the casing on the ashtray light was so old and brittle it had fallen off in parts and a lot more ended up being burnt off due to the short. i removed the wire and light bulb/socket and all was right in the world again. i personally have no use for a light in my ashtray.

[universeman]

Congrats on Maui, Dennis!

Wondering about how bad my situation is. Car seems to be running fine now without smoke or incident. I'm going to run my borescope around back there and see what I can see. Will post photos.

[brighton911]

Been there done that. My problem was the interior light wire within the harness, wrong relay in the power window circuit smoked the wire from one end to the other. Had to open the harness, not fun. 86 Targa 911 (Gerry) provided me with a wealth of info and now I am fused up anywhere where it wasn't. Like someone else said, fuses weren't one of their better points. The good news is you can make it right, it just takes awhile. Oh, and I too had a real hack job of a security system in there, where do they get those guys? Good luck

[Charles Freeborn]

Actually I disagree with the critics on Bosch wiring. I find it very logical and efficient, once you understand it, especially when you wrap your head around the "current flow" diagram instead of the point to point wiring diagram.
Lucas / British - well that's pure voodoo....not even in the same galaxy as the rest of the universe...
-C

[universeman]

Borescope was inconclusive, I'll need to tear into it if I really want to see what was damaged.

I tested the fog lights; they still work. The rear defroster switch is odd - it lights up with the key on, but goes off when the engine is started - is that normal?

[DRACO A5OG]

Nope, not normal. Better yet put a volt meter on the defrost strips to insure you are getting voltage there engine off and on.