Brock,
Unfortunately you
may be SOL for this mod, as your car is a 1999, (at least that's what shows on your sig).
It does work on Roof Relay 986.618.199.00 for 2000-2004 986.
First off, many thanks to guvs here on this forum and to dominouk on BoXa.net for sharing this information with me.
This mod is too simple NOT to do... took less than 20 minutes start to end of testing. All I used was about 4" of 20 ga. wire, electronics solder and a soldering gun. I had this stuff at home already, so this was really a zero-buck operation.
Pull the relay, then use 2 jeweler's screwdrivers to spread the cover so the guts (circuit board & attached pins) slide out. Just barely insert the drivers and gently lever out the guts. Notice how the standing PC board fits into two grooves on the cover? It will only fit back on one way. Our jumper wire goes on the back side of the board, it fits between the board and the cover. Tight fit? Yes, so the solder job has to lay flat on the board so the cover will slide back over.
Cut a 4" or so length of wire. Strip only about 3/16" of insulation off the ends, then twist and tin the ends of the wire. Tinning is simply applying a small amount of solder to the wire only. This step makes the attaching to the board easier, as you aren't juggling as many things in your hands.
Now solder your tinned wire to the points marked in red:
Carefully flatten the wire to the board as best as you can, and slide the cover back on. Now carefully bend over pin 15. It
must be bent over or it will still look for a signal from the ebrake switch. The soldering job fools the relay into believing the ebrake switch is closed, and the bent pin 15 takes the ebrake switch out of the circuit.
There wasn't enough room to bend it inwards, without it touching the pin beside it, so I bent mine outwards. It extends past the edge of the cover, but there is no interference with any pins from the other relays nearby.
Now bend over pin 18 so the relay gets no speed signal, if you haven't already done so.
Reinstall, and marvel at how your roof will now operate without the ebrake pulled up.
Obviously, we've now disabled all of Porsche's safety devices, so you can now put your roof up at 90 mph and wreck it; or
use it cautiously at slow speeds only for added convenience.