993 automatic spoiler poblems

jrgwilson · 12-03-2007, 01:58 PM

Hi All,

I've recently bought my first Porsche, a 1996 Carrera 4 manual! And I'm having lots of fun!

However, this week it's developed a fault with the rear automatic spoiler. Although the warning light goes out soon after turning the ignition (as described in the book as identifying no problems) the spoiler is not deploying at 50mph as it was before. Also, I don't have any manual override functionality through the console button either. Quite simply it doesn't want to move.

Can anyone suggest a systematic process for checking the fault please? I have done a little research so far and have located the spoiler control box in the car passenger footwell, also I have found on the net the wiring diagrams for the 993 so have some idea of which fuse is the correct one in the central fuse box (#37 15amp) and the basic circuit composition ie motors and microswitches.

I think I detect a little motor noise soon after ignition which I'm pretty sure was the norm before the problem but like I said absolutely no movement.

Any ideas of what I can check to narrow down the fault, common problems and any good fixes?

Thanks in advance

James

kang · 12-05-2007, 09:34 AM

First, check the fuses and/or relays.

Next, unplug the electrical connector at the motor. Connect a volt meter to the connectors. Activate the manual switch and see if you get 12 volts to the motor. If you do, the problem is not the wiring. If you don’t the problem is electrical.

If you do get 12 volts, and I suspect you will, the problem is with the motor or mechanical system.

You mention you get a little motor noise after ignition. Why would the motor be activated after ignition? It doesn’t get activated until 50MPH.

If you shut off the engine, and then press the manual switch, can you hear the motor trying to raise the wing?

Don Plumley · Don Plumley's Garage

There's also a diy on www.p-car.com, although it is 993 specific it might be of help.

jrgwilson · 12-10-2007, 02:48 PM

Thanks guys. I will use your points and have a go to isolate the problem. Will let you know how I get on. Much appreciated. J

jrgwilson · 12-10-2007, 02:53 PM

Hi Kang, I think the motor noise is probably just the cooling fan or similar (my mistake). I don't get anything at all if the engine is shut off and I use the manual override. The fact the warning light activates at 50mph when the spoiler doesn't deploy, I'm hoping, shows it's probably a mechanical problem and not anything electrical. Will let you know how I get on with my investigations. Thanks again.

Geoff_91Targa · 12-11-2007, 06:00 AM

I had the same problem with the same symptoms in my 964. The issue was the relay- the points were stuck in the relay and feeding it power to go down only. A new relay (which is located under the passenger seat in the 964) took care of the problem.

jrgwilson · 12-16-2007, 03:15 PM

Hi again, think I've had some success with the spoiler. After testing for power, checking fuses, testing micro switches etc, I'd narrowed it down to the spoiler transmission box (part 964-624-121-00). Using the DIY guide in p-car to open up the casing I found the bearing was completely solid. No way the mechanics could turn. I've deconstructed the box and clean all the components. Job for tomorrow is to get a new bearing and then see if I can bond the case back together (I've read Loctite 495 or even using a hot solder should do it?). Hopefully this will solve the problem and also save me $400 (#200) as this Porsche part is pretty expensive. Thanks goes to everyone for their help, I'm really pleased! J