Rear spoiler microswitch oddness.

[Alex]

Yes, the CU - control unit. Don't ask me where that is. :dont know: :grin:

 

[Alex]

Just found this online. Some gumpf on how the spoiler operates. Translated from German so a bit pigeon English, but understandable;

https://patents.google.com/patent/DE202009002106U1/en

 

[YPVS]

Just found this online. Some gumpf on how the spoiler operates. Translated from German so a bit pigeon English, but understandable;

https://patents.google.com/patent/DE202009002106U1/en

Thanks. It gives a good understanding of how the dash light works.

To be honest, I don't remember the light being on when extended nor flashing whilst extending or retracting. All I remember before the fault was it going out as you started moving. Maybe it was never right?

 

[Alex]

Mine is only on when I start the car, then stays on until you're doing over a few mph like its supposed to.

 

[YPVS]

Mine is only on when I start the car, then stays on until you're doing over a few mph like its supposed to.

The same as mine used to be. I'm guessing that patent never came into fruition, or is for a different model.

 

[Alex]

993 does it as standard, 996 does it as standard, poss 997 too.

 

[martin t]

This is a very interesting thread.

My problem, also on a cab, is that the spoiler will not work at all but the warning light does come on with ignition and go off when the car moves off plus it comes on when the car exceeds the deployment speed to warn the spoiler has not been deployed.

My problem is that I also fitted a 2nd hand engine lid and had to re assemble the mechanism (6 times so far!!!) as the Lid had to be painted before fitting to the car so have no way of knowing whether individual components actually work.

What i would like to be able to do is disconnect the engine lid loom plug and feed 12v to the motor to first off see whether the motor is man enough for the job or whether the "push rods" are jamming.

Any ideas on which part of the connector to apply 12v and also where to connect the earth to complete the circuit?

I am sort of OK at vehicle wiring but on older cars and De Morts diagram whilst being very useful is giving me a headache trying to decide where my probe should go :lol:

 

[deMort]

Your issue will be the instrument cluster can not see either the closed or raised micro switches so it doesn't know the position of the spoiler .

if you wish to test the motor on its own .. either pull both open and close relays from the rear board and power up term 30 on each or ..

From the rear wiring plug to the lid .. unplug it .. 12 volt to pin 1

Earth to pin 3 .. give it a pulse and see if the lid lifts .. from the diagram this connection is open but its possible ( as i don't trust diagrams or porsche instructions ) its the other way round .. i doubt it though .

This will bypass the switches .. the motor will not stop all the time you are powering it .

if you look at the diagram i posted ..

Top switch .. brake light for the spoiler ..

middle switch is to tell the cluster its fully open

Bottom switch to tell the cluster its fully closed .

You would use an ohm meter on the pins as per the diagram to check the bottom switch is a short circuit and if fully open the middle switch for a short circuit .. 0 ohms basically which breaks to open or infinite ohms when the spoiler is raised .

I very much doubt you have a motor issue .. the car can't see or test this .. as you have an instant warning then to me its a switch issue .

The wiring diagram to me is of a car with the spoiler in the up position hence the up switch is activated and the down is open.


EDIT ..

I would start with swapping the up and down relays .. it's possible one is faulty .. seen that before .

 

[martin t]

Thanks for that, I will try what you suggested and let you know how i got on.

I just have to find pin1 :lol:

 

[Griffter]

Mine is only on when I start the car, then stays on until you're doing over a few mph like its supposed to.

The same as mine used to be. I'm guessing that patent never came into fruition, or is for a different model.

That patent application was filed in 2009.

 

[YPVS]

That patent application was filed in 2009.

That explains that one then! :lol:

 

[YPVS]

Well, my replacement silver deck lid arrived this morning. Very good service, considering it was in NI yesterday.
It's in really good nick apart from a scratch on one corner, which I've touched up for now.

The old owner has upgraded to a GT3 fixed wing, so took the fan, rubber strip and latch hook from this, so I swapped these over from mine, but other than that, it's all there are in good, clean condition.

I've fitted it and lined it up properly and I now have a spoiler which behaves exactly as it should on the button. I'll drive it tomorrow and see if the light goes out. I expect it will.

Result for £355 delivered and on top of the £175 replacement wing and bonnet in very good condition, that's 3 panels in my spares shed now. :thumb:

Just got to do the throttle body and ICV tomorrow, now the gaskets have arrived, to resolve a hunting idle when warm. It drops to 650ropm, then climbs to 2000rpm, before falling again. I think ICV, but will also look for leaks when I clean it.

 

[deMort]

Your symptoms sound very much like a sticking idle valve .. good clean out and see how you go .. air leak is not what i would expect from your symptoms .

 

[YPVS]

Well, the idle control valve was filthy as were the passageways in the throttle body. The valve was moving when tested with a 9V battery, but after a good clean with a little brush and an entire can of carb cleaner, it turned a lot quicker.

Back together and it's a lot smoother and idles bang on 800rpm, even when warm. If you rev it, the tickover starts at 12-1300rpm, but soon drops to 800ropm within a second or so.

Much better. Smooth on idle now, so will give it another run out tomorrow.

The spoiler raises and falls on he button OK, but the light stays on when driving. The spoiler raised when over 75mph, but did not lower automatically. I'll check and replace the down relay tomorrow, as I have a spare now.

 

[YPVS]

So the spoiler retract relay isn't the issue.

The warning light stays on after pulling away, the spoiler extends at 75moph but does not retract again. The spoiler goes up and stops on the button with one touch and goes down with a press and hold of the button and stops when it's down.

Whole new second hand deck lid, with wiring harness, spoiler drive, sensors and motor, swapped both extend and retract relays. The finger now points to the control unit, but on a 996.1, I'm not sure where that it. Maybe it's part of the instrument cluster?

If it is, I can live with putting it back down on the button, when I come to a stop. I might look at disabling the warning light whilst leaving a working spoiler. I might add a second switch on the dash too. I've seen instructions with part numbers to do this on one of the empty buttons on the upper centre console.