speedometer malfunction

[mightymousestd]

I've got a 96 eclipse with a 5-spd and the last time it rained the speedo went out and won't work again...I've taken the connecting wires from the wire harness out and blew them out with an air hose cause there was water in them and I blew out the sensor on top of the trans cause there was water in there as well...both of these things haven't worked. The odd thing is that the PCM picks up the power signal from the wires but the speedo doesn't move...I think the three holes on the connector run one to ground, one to 12v and one to the pcm then to the speedo...but that's just my guess...I wiring diagram yet cause I fear I might have to rewire it possibly. another idea I have is that maybe the holes for the prongs are too loose and aren't making contact, but I put some elec grease on it and that didn't work either...sorry so long, but I think I've tried everything and I don't know what else to do short of rewiring it...any ideas?

 

[luv2rallye]

Test the voltage on the 3 pin speed sensor plug with ignition key on. The yellow wire should have around 8V. The yellow/white is the signal and will probably be at 5V when disconnected and changing between 5V and 0V when connected and car is rolling. The black/green (middle pin) should always be connected to ground (test this with an ohmmeter).

With the plug disconnected and ignition key on, if you rapidly just touch the yellow/white wire to ground and then remove from ground, the speedo should twitch (simulates a signal).

 

[GSTBlack95]

I had the same problem, but mine is only twitching every once in a while and it actually works sometimes. I have no idea what could be the problem.

 

[mightymousestd]

thanks a billion on those numbers...I was looking all over my chilton's book to find where they tested the sensor but could ever find any numbers...I can't find either how to take it out if I do have to replace the unit on top of the tranny...as I see it there is only one bolt on top of the sensor but removing that doesn't free the unit in any way...how do I go about removing it to clean it out better?

 

[mightymousestd]

I tried testing the wires and didn't get anything when I stuck the ohmeter in the sensor, so I think that maybe the wires are falling out of the back of the sensor and just not reaching the sending unit. I thought about going to walmart and getting some connectors to take the sensor off and just directly place the sensor wires on the sending unit and just taping it up with elec tape to prevent water damage if water makes it's way there again...any suggestions on to do or not to do it or anything else?

 

[the_red_pooch]

I have the same problem. I did a motor swap a few months back and while my motor was out I let the tranny sit out over night for one night and it rained, filling the plug-in. My speedo never really worked after that... Tried to clean it and everything, but nothing worked. Once in a blue moon it will work for awhile, like till I get where I'm goin and then not work again after that. You should be able to remove the whole speed sensor after just removing that single bolt, it sits in there quite well though, since it does have to seal to tranny fluid in. It should come out when you pull on it though. I went to the nearest Autozone to check out pricing to replace the whole speed sensor because I assumed thats where the problem was and they told me about $90 special order from the factory. I still haven't replaced it. I meant to just get a used one from a friend who is always parting out eclipses but I tried two of them and both were from 95-96 and my car is a 99, the plug is slightly different so I had no luck there.... Someday I will fix it!

 

[mightymousestd]

so it's just hard stuck in the top of the trans then...sad day I'll have to just pull it out...when I do, do you think you could get me one?? my car is a 96 manual trans...if you know for a fact that the sensor is good I'll buy it...

 

[GSTBlack95]

Turbo dsm's I think have it mounted differntly then a non turbo.

 

[the_red_pooch]

GSTBlack95, Yes turbo dsms are different but we both have the huge powerplant known as the 420A...

Mightymousestd, I'd love to help you out... That tranny was pulled from the car I got my motor from, a wrecked car with low miles(30k). I was saving the tranny for awhile incase something went wrong with mine, low and behold two weeks after the motor swap I messed up my 3rd gear syncro and I'm in need of a new tranny . Well I went back to my friends house where the tranny was being stored in his porch to let him know the good knews that we were about to pull my car apart again... We went in the porch to get the tranny... GONE! Someone came right on his porch in the middle of the night stealing MY tranny and some of his tools... So needless to say, I do not have that plug anymore...

 

[mightymousestd]

that sucks the big one...on a side note however...my speedo decided to start working again and it started when it started raining...go fig... sad day for third gear...it seems to be the one that always messes up...even though my second grinds a lot. happy hunting and I'll be on the lookout for some synchros...unless you already have them

 

[mightymousestd]

okay now the crazy thing just works when it wants to....I give up...my car is possessed...

 

[the_red_pooch]

On a decent note, a few days ago my speedo began to work again and now it still does. Doesn't seem to have any more problems so I'm just gonna leave it the way it is.

 

[mightymousestd]

now I think that the speed thingy in the trans (spider gear I believe) is not working right cause when the car warms up the speedo starts tripping out but when it's cold, it works fine

 

[Ultimatedsm]

Well you know the plastic gear that plugs into your tranny? Thats part of your speedo, you should test it out.

 

[mightymousestd]

plastic gear in the tranny??? on my car the wires run to a sensor that sits on top of the trans by the rear motor mount