So I went ahead and pulled #8 and #12 out of the spoiler control module plug hoping the spoiler would stay down until 76 mph as advertised earlier in this thread. The spoiler is now coming up right at 65 mph and stays up until I manually switch the center console switch with the car at rest. This kinda defeats the whole purpose of this modification if the spoiler still comes up at regular highway speeds instead of 76 mph. Am I missing something? I have a 1990 C4 with the spoiler control module under the passenger seat.

Try pulling the relay in front of the controller under the seat.

Okay, I’ll try that in the morning...thanks.

I pulled the relay and now the spoiler doesn’t come up at all and the manual switch still works!

I wish I’d known about pulling the relay first before having pulled the seat out to modify the plug. I’m wondering if pulling the wires was pointless if all I needed to do was pull the relay...

For my own edification I put the #8 and the #12 sockets back into the spoiler module plug and drove the car with and without the relay installed. The spoiler comes up at the usual 44mph and down below 4mph, regardless of whether or not the relay is installed.

So the bottom line is the mod requires pulling the #8 and #12 sockets out of the spoiler module plug and pulling the spoiler relay that’s in front of the spoiler module. This deactivates the automatic spoiler functions and, at least in my case, the spoiler stays down unless you manually switch the center console switch.

I went a different route. I modified the controller changing a resistor. It now lifts at indicated 124kph and retracts at 5okph. I did need to pull the relay.

Yeah, I’m aware of that mod... just wanted to try the quick and easy first. 🦊

from the other thread, you have disconnected the speed input signal and the spoiler alert input.

1 No connect
2 No connect
3 Spoiler moter terminal 2
4 Spoiler moter terminal 1
5 Earth/Ground
6 +12 through 15 amp fuse, always on
7 +12 from J25, switched (7.5 amp fuse)
8 F57 on central informer
9 Terminal 3 "extend" on manual switch, "spoiler up" limit switch
10 Terminal 5 "retract" on manual switch, "spoiler down" limit switch
11 Common on manual switch
12 G56 - speed signal
13 No connect
14 No connect

Thanks, John. Always love wiring schematics!