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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.

pics:

m86025_dscn2765.jpg


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

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Our 99 Forester speedo will intermittantly "sticks" at 43 mph. Rapping the instrument panel on the left side a couple of times fixes it temporarily. Does my symptom fall under the same heading as a faulty ground?

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Great information. You should post this in the USMB repair manual forum so that it won't get lost in the future.

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.

 

pics:

http://imagehosting.gr/gallery/3450-Subaru-Legacy-1999-speedo-problem/

 

 

m86025_dscn2765.jpg

 

 

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

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i have no reason to believe that the information above is not accurate, but i might hold off on making it a permanent part of the board until we have some successes.

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Okay, so I have a Subaru legacy outback 99. My speedo was not working all the time. I read this post and decided to try the fix. Note: When I held the trip button my speedo would kick back on so I figured this fix would work.

I pulled all apart on the dash like the thread say's and got to my speedo circuit board. I put solder as indicated to replace the ground. The wire needed was tiny and hard to come by at my house but I found one. I had to hold it using tweezers and a third hand was handy here.

That all being said, I put it back together and Voila...it works again. Thanks for the original post John.

 

max

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i have no reason to believe that the information above is not accurate, but i might hold off on making it a permanent part of the board until we have some successes.

 

I had success, it was easy if you have small fingers.

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Would this work in a 97 subaru SVX?

 

i have no idea.

 

usually a speedo problem is the speed sensor. but 99s have a ''bad'' ground.

 

what is your speedo doing?

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One day I passed someone and hit the gas kinda hard and my speedo just dropped to 0, and it wont count miles and my cruise control quit working also. every now and then when I keep a steady speed the needle will jump and plays around the speed Im going but the second I slow down/ take my foot off the gas it drops back to zero, I am fixing to go on a road trip and it would be super nice to have my speedo back. if you have any ideas let me know please :)

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generally if the cruise does not work the problem is not the speedo, it is the speed sensor. if the speed sensor is bad it will also cause FWD only, no AWD (no power to the rear wheels.)

 

auto or manual?

 

does any one know if a 97 SVX has a cable driven speedo? i assume not but thought i'd ask to be sure. legacy changesd in 95, impreza in 96?

Edited by johnceggleston

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Its an auto. is there anyway

i can test this before

i buy the part, and do you know exaactly how to replace the speed sensor?

Thanks so much for the info!

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Its an auto. is there anyway

i can test this before

i buy the part, and do you know exaactly how to replace the speed sensor?

Thanks so much for the info!

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Great info. I recently ran across a bad '99 speedo. Unfortunately I replaced it with a new one - wish I had seen this sooner.

 

My dealer says this is a problem with ONLY '99s. They carry two speedo heads in stock just for this purpose.

 

GD

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i can test this before i buy the part,

and do you know exactly how to replace the speed sensor?

causes range from a bad wire connection to bad speedo gears in the trans and of course, a bad sensor.

 

EDIT: my first step might be to remove the instrument panel and check to make sure the wires are connected and that the mounting screws are tight on the back of the speedo. if the screws are loose that is likely the problem. if they are tight, read on.

 

the VSS #2, speed sensor, is located on the passenger side of the auto trans above the front diff dip stick. you can access it form the engine compartment. there is a 2 wire harness that drops down from all the other wires on the rear of the engine. it plugs into the top of the sensor, which threads into the trans.

 

you should be able to remove the sensor with a box end wrench, i want to say 7/8 inch but that may be too small. or you may be able to use a deep well socket?.

 

there is no easy test. and it is a is little odd that it has not caused a CEL. but that happens sometimes.

 

i have tested speed sensors by attaching the ''tab'' on the bottom to a piece of rubber vac tubing and then an electric drill. attach a volt meter to the connectors and SLOWLY run the drill (roughly speaking, 800 RMPs = 60 mph i don't want to think what a 3400 rpm drill could do to a sensor.) the needle should jump up several times for each rotation.

 

this probably doesn't make much sense, sorry. the sensor it driven by the speedo gears in the front diff. for every rotation is sends several ? pulses to the speedo. these pulses are simple electrical pulse and can be measured with a volt meter. so you want to rotate the speed sensor drive ''tab'' and see if the volt meter moves. just a guess, but at some point ''too slow'' probably isn't going to send a pulse??

 

if the needle does not jump, the sensor is bad .

 

another test, inset a flat screw driver in to the ''slot'' on the trans that drives the sensor. jack up the front passenger side wheel and rotate it by hand. if screwdriver turns then the speedo gears are there and working. (you could even do this with the sensor in place and the volt meter attached to the wire connector. probably easier than the electric drill.)

 

i would probably go with a used part. someone here should have one. ask here or post a WTB ad in the classifieds.

i don't know if you can buy one on www.car-part.com ? but there should be plenty of them around. if you go to a yard to get one, try to get part of the wiring harness as well. it may make it easier to connect a volt meter.

 

what did i forget?

Edited by johnceggleston

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Would this work in a 97 subaru SVX?

Do you ever get the speedo popping back on or does it come on when you hit the trip while driving ? These were the symptoms I had.

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Just did the soldering task... seems to be working so far.... (although the odometer seems to be a bit wacky)... man oh man, there must be an easier way to accomplish this... perhaps an 8 year old's hands would work better/quicker/easier... less physical damage to my own hands....

good luck to me.

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so....

one month later & it's all happening again.

I figured my solder joints had come undone... I took it all out again. (even more fun the 2nd time around...

solder looked intact.

lost 3 of 4 screws putting the diplay back in & lost the magnet I was using to find them... oh well.

seems to work now... hope it lasts this time.

later,

Peter

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& another month down the road... a couple of speedometer needle drops to zero... & then most of the time: no speedometer.

took it out

did it again

maybe 3rd times the charm?

hope so...

later,

Peter

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On first attempt, this worked fine. I'll update if that changes. '99 OBW 2.5 5spd, already changed the sensor and checked the wiring harness.

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Hello,

 

I saw this and I thought I would try it. Well my Speedometer worked but the check engine light came on. So I took everything apart and undid the wire. Put everything back together and check engine light went out, did not drive the car afterwards. My car just came from the transmission shop and they said to replace speedometer. So this is a failed fix in my case. 

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Hi there. I thought I may throw in my two cents, since (cents?) I work at a speedometer shop.

As far as diagnosing why ones not working, as johnceggleston mentioned, if speed and odometer quit at same time, and cruise doesn't work, then there's probably no input from speed sensor. Either sensor bad or a critter chewed the wire (side track- I heard somewhere subaru didn't use the soy-based wiring insulation a lot of manufacturers are so mice and whatnot are less prone to chew on a soob. Any knowledge about this?) anyway, an electric speedo works on frequency (Hz) and some nice multimeters have a function to test this. You would see Hz go up the faster it spins (electric drill is usually fine). No idea the calibration of one of these. It can also be checked on regular dc volt setting, it will show a very low voltage that just jumps around as it spins, so at least you can tell it's doing something. If this checks out good then trace wiring and all connections. As outlined by this repair, I've seen a lot of failures due to simple cold or dirty solders or seemingly benign corrosion on a connection.

I'm glad someone discovered the common problem, I may even get to use it at work. Otherwise we don't really repair any of the modern Japanese electric gauges as there is no info or parts available. Dealer wants to sell you a replacement. But if there's other speedo or gauge issues w any Subarus I'd be glad to look into it anyway, for the sake of the forum.

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