Replaced the PNP switch in my '95 850 GLT about 5 months ago after the dreaded yellow arrow of doom contintued to show up on the dash. the car was refusing to start in low, went directly to third gear and had me greatly worried. I isolated the problem to the PNP thanks to volvospeed and this board. My mechanic checked out the car and said that the PNP was fine and then charged me $300 for his diagnostic time and flushing the transmission. Car ran OK for a day and a half and started doing it again. That was it for that mechanic. I got the directions from Bay13 and went in. You have to move a bunch of stuff out of the way just to get at the switch so do whatever makes you feel comfortable so you remember what connects to what when you put it back together. Take notes, take digital pictures, label everything with little tape flags, whatever. Switch replacement is very straightforward. Just don't turn the shaft sticking out of the transmission while you remove the switch (it takes a deliberate effort) or you will be out of sync with what the shift lever indicates (instead of park you will be in first gear, etc.). Mark the shaft with a dot of nail polish or paint and a corresponding dot on the trans so you can get it realigned if you're concerned. If you happen to turn the shaft it's not the end of the world, you'll just have to futz around until you get it sync'ed again. the Bay 13 instructions are excellent, so suck it up and dive in, it's more tedious than anything else. Good luck!