garrett376

A while back Ruf (I think that's who it was) was offering an exchange program where the spoiler control module was updated to change the speed that the spoiler elevated to 75mph. Did anyone buy one of these modules? If so, I'd love to see a picture of the internals to compare with a stock one - I am curious what was changed.

I am also trying to figure out a way to make the rear spoiler so it is controlled entirely by the switch on the dash - with no automatic elevation based on wheel speed...

mxbanker

I did not get one sorry but I sure like the manual only idea.

garrett376

I've been brainstorming while looking at the wiring diagram... before I get sweaty cutting wires in the garage, I thought I'd see what everyone thinks first - check my logic:

Facts (regarding post-89 964's):
1. spoiler can be raised or lowered by the dash switch even when the warning light is illuminated

2. spoiler can be raised even when the spoiler control unit has received no speed signal input yet from the speedometer

3. the spoiler warning light is deactivated by unplugging the control module

Theory:
1. cut the white/red wire (pin 12) to remove the speed signal input to the control module reason: this will disable the automatic raising of the spoiler without disabling the dash switch

2. cut the green wire to remove communication to the central informer to disable the spoiler warning light reason:so that when the speed signal is disabled, the warning won't appear (similar to when the control unit is unplugged in entirety)

It seems that by doing those two simple disconnections, the automatic function of the spoiler will be disabled, and no warning lights will appear, yet the spoiler can still be operated with the switch on the dash.

Sound good?

mxbanker

Sounds correct but i dont have to be the guinny pig do i?

Bill Wagner

It might work, but it's sort of a "crap shoot". Most of these circuits probably expect to see an impedance of some type on their output stages. Cutting wires essentially "floats them" to an open circuit (very high impedance). I would think this MIGHT (and I mean MIGHT, not WILL) cause a fault to be recorded. Possibly you could "ohm out" the connections before trying this, or better yet analyze the input/output circuitry and match the impedances. On the other hand, since you can always re-splice the wires I doubt that other than possibly recording and storing faults it's probably a safe experiment.

garrett376

Good point Bill. I think the reason this will work OK is that you can just unplug the entire module, and no faults are recorded - so it seems it should work to simply cut them out. Plus, it seems my unit has an intermittent connection in it because it will sometimes work, other times the spoiler warning light will remain on at speed, and I have to tap it with my hand (or hit a big bump in the car) to get it to extinguish the light and function normally! Even during intermittent operation, I can utilize the switch on the dash. This makes me think my speed input is intermittent - so cutting it entirely should do better. Plus, it does not seem that any faults are recorded for the spoiler - it either works, or it doesn't and a light is activated on the clock.

MX - no, don't worry - I'll be cutting my wires tomorrow!

mxbanker

Garret

Dont know which of your cars I like better?

Kinda partial to your grey cab(ya think)

But my gone but not forgotten 911T was a black coupe!

springer3

Garrett:

The intermittent fault is almost certainly a cold solder joint on the circuit board.

If it helps, I have about half of the schematic for the controller for a 92. Regrettably, the speed for raising the spoiler is sensed digitally, and therefore it is difficult to fool the system. I gave up. Mine at least works as designed with no intermittent faults.

Red rooster

Springer3,
Looking at the pic of this unit it looks like a Bosch? custom controller with a crystal clock.If you wanted to change the spoiler switching speed could you just change the crystal freq. pro rata . 10% more speed = 10% higher frequency.
( Provided the freq. is within the limits of the controller )
I have certainly done this with other similar stuff .
Geoff

garrett376

Hey Geoff - I was looking at that little crystal on there (the silver clipped oval can) and was thinking the same thing as clocking up a computer system... but then wouldn't there be two - one for the low speed, one for the high speed of activation?

I'm going to try cutting the wires first!

springer - what would be "clicking" inside the unit itself? The copper-wound units?

EDIT: figured out that it is the 2 copper wound things that click - I can push on them and move them around to make the same noise I hear while driving. Sometimes it clicks a lot - like 1 every second for about 5-6 seconds...

garrett376

So far it works!!!
It is nice because this entire project is reversible - in the pics below you can see how the plug can be opened and pins 12 and 8 are removed, then the plug snapped back together, and plugged into the control module. So, no wires are even cut, for those of you not wanting to cut into the electrics.

Here's what happens: with the control unit plugged in, when the ignition is turned to on (not yet start and running) the spoiler warning lamp lights up - this is due to the central informer doing its full test, I assume. Then, when the engine is started, the spoiler light goes out!

Now, while the engine is running, or when the engine is not but the ignition is ON, the spoiler control switch on the dash is fully funtional - it raises the spoiler and stops at its limit, and the same for closing the spoiler - so the switch's function is unchanged.

So far, so good. Now I need to find a place I can get to 50mph without killing someone to see if this works perfectly!

garrett376

Ok guys and gals, it works! Success!!!

I go over 50mph, no spoiler raise, no warning light, but I can raise and lower the spoiler at will with the switch - it functions exactly how I want!

I did the "modification" to my cabrio- it takes about 2 minutes to perform on later 964's:
1. unplug the control unit wire harness (you don't even need to unscrew the control unit from the bracket) - 90 and 91 cars I think have this unit under the passenger seat so it might be a bit more difficult to reach it...

2. holding the plug from the wire harness, use a flat head screwdriver to pop off the back of the plug to see the wires

3. Slide out the #8 pin (green wire), and #12 pin (white/red) - they are labeled from the mating surface of the plug

4. Fold over those wires so you can close back up the plug - snap it back together

5. cover the wires with electrical tape, plug everything back in

You are all set! You will now have a spoiler that is activated ONLY by the dash/console switch - it will no longer come up at speed. This was done on my 92 964s - so I would assume it would work for any post-89 964, but I am not sure about it. Also, I believe the 92, 93, 94 all have the control unit above the passenger's feet, while the early 964's have the control unit below the passenger's butt.

Marc Shaw

Sounds impressive but I'm not sure about the reason for this -- isn't the speed activated raising there for a reason so why do you only want to do it manually?

Marc

FlatSix911

Great mod - is the spoiler control unit the same on a 1995 993?

John Boggiano

Ditto what Marc said.

What are you gaining by it, Garrett?