dash cluster smokes

[pficarra1@rochester.rr.com]

I have a 1999 Boxster with 94k on it that I have owned for 3 months in which time it has always run great. It has cel on for an issue with the fuel tank area(1126/1124) but that is not my concern at the moment. When I turn the head light switch on smoke comes out of the instrument cluster and I am sure the car would burn up if I did not turn the lights off! This started with the dash lights not working behind the tach etc. I tried to turn the dimmer stalk and the smoke started so I unhooked the new battery. I had a used cluster and I pluged it in and as soon as I turned on the light switch it started to smoke too. Could this be the light switch? Also the battery was unhooked over night and the car starts but runs rough. HELP

Edited September 9, 2009 by pficarra1@rochester.rr.com

[pk2]

What you probably have you can call a slow burn short... that can be where you have big wiring is shorting or has a bad connection but is just a little bit bad. Not enough to pop a fusem but given time can burn. Like a soldiering . A short circuit that is hot but won't blow a fuse

The beauty of this is that the wire will be pretty obviously burnt. However the short could be on the on either end of said wire or a device on either end,

A good thing is to start at one end of the problem. like the fuse box or the lights and trace the along until you find something fishy..

There maybe a very comon problem, I don't know about, but I'll leave that someone else

Edited September 9, 2009 by pk2

[pficarra1@rochester.rr.com]

Thanks for your reply, I will check the wiring but what I do not understand is how I can have a beautiful black beauty to drive one miniute and a dash smoking the next. This is my fifth Porsche and the others were a 944 turbo, a 928 and 2 911's. They have been trouble free bullet proof cars until this one which is the newest by the way and before this was on the way to being my favorite until the dash started to burn. I like mid engine cars as I have had two Pantera's, and three Ferraris etc and I will post the outcome as it plays out. Thanks for your suggestions and this forum is great for us diy guys.

Pete

[N41EF]

I'm an electrical guy, but not a boxster expert, here's what I know. The fuse box is in the drivers kick panel below the headlight switch. If you are getting something hot enough to smoke there should be heat damage to the wires. I would disconnect the battery and pull the cover off the fuse box, there are a couple of screws that will allow you to pull it out and inspect behind it. Then pull the duct below the steering wheel and inspect the back of the headlight switch. Also pull the cluster and look down to the left to see if you see any damage. I've seen amaizing things people do to cars wiring. Maybe someone wired a radar detector and left a hot wire, you never know what you will find. Let us know what you find.

[pficarra1@rochester.rr.com]

I looked at it for a while today, could not figure how to get the light switch out. The panel its in has 2 screws on the side but only pulls out on the side not by the switch. any suggestions?I removed the panel around the fuse box but saw nothing there. I pulled both lights out and the front carpet etc but fould no burnt wires. All the lights work by the way. I turned the lights on, and sure enough it started to smoke on the left side of the cluster which was loose but not attached. I unpluged the blue plug on the back, leaving the other three pluged in, and it did not smoke any more. Any one have a diagram that shows what the blue plug gos to?

[Loren]

I looked at it for a while today, could not figure how to get the light switch out. The panel its in has 2 screws on the side but only pulls out on the side not by the switch. any suggestions?I removed the panel around the fuse box but saw nothing there. I pulled both lights out and the front carpet etc but fould no burnt wires. All the lights work by the way. I turned the lights on, and sure enough it started to smoke on the left side of the cluster which was loose but not attached. I unpluged the blue plug on the back, leaving the other three pluged in, and it did not smoke any more. Any one have a diagram that shows what the blue plug gos to?

Search is your friend...

http://www.renntech.org/forums/index.php?s...ost&p=14785

[pficarra1@rochester.rr.com]

LOREN, Thank you!

I did a search for "remove light switch" and it gave me many pages to sort thru. I must be doing some thing wrong? How do I narrow it down?

Thanks,

Pete

[Loren]

LOREN, Thank you!

I did a search for "remove light switch" and it gave me many pages to sort thru. I must be doing some thing wrong? How do I narrow it down?

Thanks,

Pete

"headlight +switch" works better

[pficarra1@rochester.rr.com]

My dash still smokes when I turn my head lights on if the blue plug is pluged in to the cluster. Does anyone know what the blue plug connects behind the dash so I can narrow my search for the short I have. I have pulled the light switch and fuse box and see nothing burnt in either. Why caint these cars just blow a fuse that links it to the short instead of burning up the car? I do not want to dismantal the whole car. I have had no luck searching the site for wire diagrams for any of it.

[N41EF]

I checked the wiring diagram in the Bentleys manual. The blue plug only has three wires that seem to corespond to your issue:

Pin 8 is for the High Beam Indicator

Pin 10 is for the LED dimmer

Pin 11 is for the bulb dinmmer

Also of note, when you turn the headlights on, power goes from the swith through fuse A5 to the cluster (though I can't find where), the a/c unit, anf the tag lights. Pull that fuse, and see if it continues. You'll lose your tag lights, but it should disconnect the headlight switch from the cluster.

It looks like when the lights are on, the dimmer is then in the circuit, and voltage is reduced through the cluster to dim the dash and switch lights and all of the led displays. This is all power going FROM the cluster to the other lights.

Check the wires for those three, also since you haven't owned the car since new, check for yellow colored wires in the plug, they aqre replacement wires, indicitive that some one has done electrical work on the car.

Let me know what you find and I'll try to help.

[pficarra1@rochester.rr.com]

N41EF,

Thanks for your help. I pulled the A5 fuse and it did not smoke. Plug it back in and it smokes. There is a yellow wire in the lower left hand corner as you face the holes in the plug. The wrapping around the harness looks original. Could there be some kind of relay shorted? It all started with the dash lighs not working and a smell of wires burning with the first cluster. The second cluster still has dash lights but both smoke with that fuse in. does that narrow it down? Can I by pass it? Is the front trunk light on the same fuse, it has not worked since I got the car and the bulb is good.

Thanks,

Pete

Edited September 16, 2009 by pficarra1@rochester.rr.com

[N41EF]

A5 is the power from the headlight switch that tells the cluster that you've turned the lights on. It also tells the ac unit the lights are on and dims those leds. It sends power to the tag or license plate lamps and to the rear "position" lights which I believe are the rear corner lamps.

If pulling A5 makes the smoke stop, you could drive the car with the fuse out, you just lost your tag lights, and the cluster lights and A/C lights won't dim when you turn on the headlights.

The front trunk light is not on the same fuse, mine acted up too when I bought it, it was a dirty contact on the front latch that controls the light. I flipped the front latch several times and the lamp came on.

Yellow wires are repair wires, when I added my cruise and OBC it was explained that yellow wires means someone has repaired or added something. If it is a solid yellow wire, follow it to see where it goes. The smoking comes from a wire getting pinched or shorted, there are no relays between those two points.

If you are good with a miltimeter, I would disconnect the battery, connect an OHM meter to the A5 load side and turn on the headlights to check for a short, you could remove the taglights, and marker lights to make sure you aren't just reading bulb reesistance. It will take a while but following the wire from A5 to the cluster, somewhere along the way you have a short to ground. Your going to want to remove the cluster, the kick panel around the fuse block, the vent tube at the drivers feet, and maybe the driver's outside vent (the one above the headlight switch. SOMEWHERE between those two is a ground causeing the smoke.

Sorry for the delay in getting back to you, work and college fills my days and nights.

Let me know what you find, Chuck

[pficarra1@rochester.rr.com]

Chuck, I gave up and I took it to a German car shop and they just called me and guess what? It was a bulb in the ashtray Which I never use or look at that was shorting out? By pass that and they say it is fixed! Thanks for all your help and could I add you as a friend?

Pete

[N41EF]

Chuck, I gave up and I took it to a German car shop and they just called me and guess what? It was a bulb in the ashtray Which I never use or look at that was shorting out? By pass that and they say it is fixed! Thanks for all your help and could I add you as a friend?

Pete

Glad it worked out for you. Tracing grounds can be a nightmare. Obviously A5 somehow powers other lights than those listed.

Chuck

[ktfaut]

Mine is a 2000 Boxster base. Much the same scenario as befell Pete in '09: Turn on headlights, try to adjust the dimmer for the tach and the speedo, smoke begins to emit from the dash - very creepy. Having read Pete's mechanic's discovery regarding the ashtray light, I can say I have looked under the ashtray, a place I keep some bills and change, and sure enough there is what appears to be a "smashed" light bulb at the bottom. Who would have thought. I shall pull it and try to replace it to prevent further short circuits or "grounding." Will still have to pull the cluster as there must be a burned wire within.

Pete mentioned mechanic said "by pass that," presumably implying bypass the shorting bulb. Perhaps pulling and/or replacing is equally as effective.

Appreciate the input from Chuck as well regarding fuse A5. That's the first place I'll look.

Kurt