Jonathan Russell

Hey All,

2nd time posting about this, I'm hoping to get some help this time. My 2000 C2's turn signals do not work along with the horn when pressing it on the wheel (horn works with alarm)

Items replaced or checked:

• headlight switch replaced (was burned)
• hazard switch replaced
• ignition switch replaced
• Fuses swapped
• Relays 3 and 16 checked with 9 volt battery (might need rechecking)
• Headlight grounds in frunk checked and cleaned

Related things are the front parking (amber) lights won't turn on but the rear ones light up, the gauge pod buzzes when lights are on and hazard switch is depressed, buzzing stops when hazard switch is pressed.
Thanks in advance for the help.

Paul Waterloo

You have a bad ground in the car/electrical circuits and power is back feeding through the other circuits to find ground. You need somebody who knows how to read the electrical schematics and troubleshoot. It's not hard work, just tedious. Best of luck.

Jonathan Russell

I could try doing this but would taking it in to an independent shop be best? I'm thinking it's not more than 4 hours of work and no parts?
Just take it to the shop?

Horsepwr

Definitely a bad ground

Paul Waterloo

If you could find somebody to troubleshoot it and fix it in 4 hours, he would probably charge $250/hour. I consider myself an expert electrical troubleshooter and this is something that I would have to study for a few hours before I even dug into the car. If I went out on a Saturday morning and started at 8 AM blind and fixed it by noon, I would figure I was an absolute genius!

You can download the workshop manual with the electrical schematics here: http://audipages.com/911/wsm/

You'll need those first.

Paul Waterloo

Please post a more detailed list of the issues above, for example:

My 2000 C2's turn signals do not work along with the horn when pressing it on the wheel (horn works with alarm)

What does this specifically mean? The turn signals work if the horn is NOT depressed? The turn signals don't work? How does the horn work with the alarm? That does not make sense to me, i.e. it needs to be clarified.

Post all of your symptoms in detail and maybe I can look at the wiring diagrams. It's definitely a bad ground.

Paul Waterloo

Here's what I would do:

• Download the repair manual, open the wiring diagrams
• Go to sheet 17 which is the ground points. The numbers and letters in boxes such as "F83" comes from the sheet with 83 on the Y axis and F is the location on the X axis. The wiring diagrams start at 1 and continue to go to higher numbering. So it's pretty easy to find your load on the proper page, then determine where the ground point is by going to sheet 17 once you follow the ground path (the other page will show the power supply location).
• Look at the ground points in the frunk (sounds like you had, ground point 2 is on the left, that is the horn ground point)
• Physically take a wire (a set of jumper cables would work) and jump the ground location to the negative on the battery so you are providing another path for ground.
• Test the horn, lights, and the turn signal.Does anything change?

I also see that the instrument cluster has the buzzer, controls the turn signals, etc. I would check the grounds and just important, the connection to the instrument cluster on plug II, which is the white plug. Go to sheet three, see the top two lines, they are terminal 31, which is the ground circuit, there are (2) connections II/8 (connector 2, pin 8) and II/21. You need to remove the cluster, unplug the connectors, if you have "detoxit", use that to spray the connections and re-insert the plugs and test it. Even if you don't have detoxit (just google it), disconnect the plug, inspect, and plug back in and test. Super easy to remove the cluster on these cars. Test everything with it out.

The instrument cluster goes to ground at L168, that is on sheet 17. I would personally run a wire from the battery negative and perform a resistance test with plug II removed to pins 8 and 21 to ensure you have a good connection. If you do, there could be an issue in the instrument cluster or at the connection to the instrument cluster. The instrument cluster is grounded on the "Electronics Ground" is somewhere behind and below and cluster. If you find that first, you can always do a resistance check to the battery negative from there or do the jumper cable (or any larger wire with alligator clips) from that post to the battery negative and test to see if things work. If it still does not work, it's upstream, i.e. somewhere between that ground point and the load, such as the instrument cluster connection or inside the instrument cluster.

Remember, the issue is almost always in a connection.

Here is the ground points in the car:




And here is where the instrument cluster grounds out:

jllphan

While a ground issue may be the culprit it could also be two unrelated issues. The inopp horn is common and you can search around for the parts needed to replace/fix. As for the turn signals, does the stalk function as it should? Does it engage and lock by flipping up or down? Do the lights flash when engaging the hazard button? If the hazard switch happens to be bad or partially pushed in, it will prevent the stalk from functioning as it should. I’d suss all that out before tearing into the wiring or hiring a third party to diagnose. A bit of googling got me to that point, there’s lots of info online if you care to search.

Jonathan Russell

Thanks for taking the time to look at this with me. Here is a more detailed description of what I'm encountering:

• The turn signals never work, never make a sound or light up in the gauge cluster.
• Turn signal stalk and switch physically works perfectly for all stalks, cruise control and wiper stalks work perfectly.
• The horn never makes a sound when depressed, I can hear the switch clicking when it is pressed.
• The front side markers and parking (amber light) lights never light up, never blink for turn signals. Bulbs checked and look ok. Checked both GP 1 & 2 and was clean and looked brand new, traced the wires from GP 2 to front bumper and all looked good. Nothing lit up when trying to clean or diagnose any of the connections.
• Rear parking lights work, brake lights too, turn signals do not.
• When lights are on, the gauge cluster does not illuminate, and makes a buzzing noise, when hazard light is pressed the buzzing stops and gauges illuminate.

I think the gauge pod was changed due to build code aluminum trim not being on my gauges, but I could be wrong. It is white faced gauges with no aluminum trim. Is the electronics GP in the above diagram under the gauge pod?

De Jeeper

Im thinking u may have a clockspring issue. I have not specifically looked into these symtoms in porsche but your symtoms r similar to clockspring issues in jeeps.

Paul Waterloo

I would do what I suggest in the post above. Pull the instrument cluster and check the ground points on the back of it. I'm uncertain where the electrical ground point for the electronics is it's either behind the instrument cluster or it's above or behind your feet pedals.

Jonathan Russell

Hi Paul,

Pulled the pod cluster and pulled the hazard switch out. Checked all pins and pod connections and all looked good. I believe the female hazard switch in the dash was upside down, when I tested the switch with hazards it immediately worked. Reinstalled the pod and turn signals work good as new. The horn does not work still, going to check with volt meter soon but this was the big one.

Take a look at the ground points, thought the scorch could be from a faulty arcing ground but it looks more like factory weld marks? Please confirm.

Under dash cluster ground points. Left side

Under dash cluster ground points. Right side

Paul Waterloo

Jonathan-

That's awesome news! If everything works but the horn.....that will be easy to troubleshoot. The factory ground points look normal to me, I'm sure that's the way it's always been.

When I looked at the wiring diagrams the other day, the main horn is a different horn from the alarm horn.

I will look at the horn circuit.

Paul

Jonathan Russell

I could use help finding out if pressing the horn completes a hot circuit by providing a ground or if it provides current to the horns. The parking lights work up front now too.

Liam582

Thanks for the guide friend! I have a small problem with the electronics in the car, nothing critical, I'm sure I can handle it myself thanks to this manual.