Rear Spoiler Not Working
 

I have a 1999 Boxster and the rear spoiler does not work manually or when driving above 75 MPH. I changed the fuse and relays in the rear trunk. What else can I do? How do I diagnose the problem? What can be the problem?

There are a few things that control the rear spoiler. There are some fuses and relays in the trunk as you have seen and investigated. There is a switch on the fuse panel that will control it up and down, does the spoiler work when you power this switch? I have heard that you can adjust the speed level at which the spoiler goes up or down, but I have not been able to find this setting in the PST-2 computer.

-Wayne

Spoiler Not Working At All
 

Hello Wayne,

The spoiler does not work at all. I tried it manually and tested it while driving all the way up to 80 MPH. I changed the fuses under the front dash and relays in the trunk. I also cleaned the spoiler electrical connections. The Bently book says that the spoiler has to come up in order to take the spoiler motor out, but the spoiler does not go up so I can get the motor out to test it. Anyone have any suggestions at all? Is there anything else I can do to diagnose the cause of the problem? Or how to get the motor out?

The switch should make it move, unless the relays are dead, and/or the fuses are blown. I'm guessing it's an issue with something like that. You can also apply 12V power directly to the motor of the spoiler. It also might be something to do with the switches in the unit. I have some information on it in my article here: Pelican Technical Article: Boxster Rear Spoiler Installation - 986 / 987

You just need to get in there and start troubleshooting. Also, my article on electrical troubleshooting might help too: Pelican Technical Article: Troubleshooting Electrical Problems on Your BMW

-Wayne

Try the obvious just lubricate the shaft and make sure nothing is holding it back or blocking its movement.
Just had mine fixed – not sure if this is going to help u but thought to share it – my car was hit in the back and a screw holding the rear bumper came lose and needed fastening. The screw was holding something close to the spoiler and every time it tries to come back it was holding it down.
However the interesting part is the hydraulic shaft responsible for the spoiler movement became dry, with a bit of lubricant – white grease – it works as expected.

I have a problem with the rear spoiler not going down on my 986, automatically or with the footwell switch. (It goes up at 75mph as it should but then stays up.) Sometimes the footwell switch works and it goes down all the way, sometimes the spoiler moves down a few mm then stops and won't go any further, but mostly it doesn't do anything. Checked fuses, relays. When directly wired to 12v it works fine so motor etc ok. Checked control unit under seat for water ingress but bone dry and wiring all good. Any ideas?