has this been posted before?
i found this over on the legacy gt forum and thought it should be included here. i was impressed.
apparently the cause of the 99 speedo failure is a bad ground connection on the speedo circuit board. by adding a a wire to replace the bad connection the speedo will work again. and although you have to pull the speedo to fix it you do not have to remove the circuit board from the speedo. (EDIT: i've been looking at the pics and i'm not sure you can fix it with out removing the circuit board, FYI.)
the the blue "s" shaped wire is the fix, see the pics.
write up, not by original fixer:
So I just had this problem in a 99 Legacy Outback that I got and searched the internets and found the solution(at least to my particular problem). Here's a test, if your speedo isn't working and you push in the trip odometer and it starts working again(however briefly) then both of your speed sensors are just fine. The 99s seem to have a problem with a ground in the chipboard of the speedo unit itself. Here's how to fix it. Sorry for the lack of pictures but i'll try to describe it in detail.
Start by unhooking your negative battery terminal so you don't zap yourself and/or set of the airbag accidentally.
Remove the two screws at the top of the shroud covering the speedometer and the two at the bottom as well underneath the switches(fog lights cruise). Now the whole shroud should come off with a little persuasion and you can get your hand or fingers in there to pop off all the wiring harnesses to your different switches(cruise fog lights etc.) Remember where they are, or as I like to do, take a cell phone picture.
Now there are two more screws on the top and two more on the bottom holding your speedometer cluster in place. Remove all of those and wiggle your speedometer out a little bit. There are a total of 4 harnesses to disconnect, one on the top left, two on the top right, and one directly in the middle(the speedo "cable")
Take the whole cluster out and bring it inside to work on a table or something. Take the cluster apart by removing the plastic shield in front and unscrewing the 5 screws right behind the speedo head in the back of the board by where the speedo cables' harness was. When you get the whole speedo head out, pull off the chipboard and look at the middle pin of the 5 pins that the harness plugs into. It has a chipboard wire going a few mms to a soldering point called ground. This is the problem with your speedo. The 99s have a bad connection to that ground.
THIS IS REALLY EASY!!! all you have to do is take a small wire from anything and solder it to the middle pin and solder the other side to the ground. Voila. You're done! You just bypassed the bad connections on the board with your own wire and now it has constant ground and will be happy. Put everything back together the same way you pulled it apart and your speedometer will be eternally grateful.
I had never taken any part of my interior apart, and done VERY little soldering or dealing with chipboards before, and the entire process took me about an hour and a half.
hope this helps.
taglines: speedofix, 99speedofix
Edited by johnceggleston, 16 December 2013 - 07:38 PM.