View Full Version : Speedometer stopped working...kinda

05-19-2003, 04:43 PM
I just got the car last thursday, and it has worked fine everyday that I have driven it. It worked fine this morning and at lunch, then I started it up, started driving, it worked fine. I then got onto the high way, and noticed it was stuck at 40, then it shot up to around 70 and stayed there the whole time I was on the highway. Even after accelerating and slowing down it stayed at 70. I got off the highway, got stopped at a stop light, it went down to 20, then 0 after about 6 seconds of me stopping. Anyone know what could be the problem?

And also, 95% of the time my car starts fine. But sometimes it seems like it turns on and is running, i let go of the key and it turns off. It has only done this when it is really hot outside. Anyone know what could be wrong here?

Duffy Floyd
05-19-2003, 05:25 PM
Pull the speedometer and look inside of it. I had the part number tag fall off into the guts of the speedo and it jammed the needle and odometer from working. This assumes your speed control has continued to operate normally which means the VSS (Vehicle Speed Sensor) is working.

Mike Puckett
05-19-2003, 08:10 PM
If the speedo needs repair, the Speedometer Service Co. at http://www.speedometerservice.com in Roswell, GA, a northern suburb of Atlanta, can repair them for $85. There is a gear inside the stepper motors that move the pointers that breaks. They won't sell the little gears but they'll repair the units.

05-19-2003, 11:06 PM
it is working now. I think it was just one of those freak things. *knocks on wood*

05-22-2003, 08:47 PM
Ok, it started doing it again. I was on the highway, cruising in 5th and i dropped it to 4th and floored it. The speedometer cuts out at 70.

05-22-2003, 09:58 PM
Like Duffy said...I also had the sticker fall inside the guts of my speedo and stick it at 70.

05-23-2003, 06:23 PM
similar problem happend with my SC a few weeks ago, except that when i drove the speedo went all over the place, and when i stopped it buried itself at 120 and the odometer ran... sucked. turned out the speedo cable under the car was dirty at the connector. just clean the connection point, worked for me.

06-28-2003, 10:52 AM
I just had problem where my speedo climbs up to whatever speed but wont come back untill I lightly depress the trip odometer reset, then it drops to whatever speed I'm traveling. The counters, both regular and trip both function, and so does the cruise. Is it hard to pull the unit to check for junk in back or does anybody have any ideas?

06-28-2003, 11:01 AM
Either the aforementioned problem with the sticker falling off and causing a physical bind of the speedometer, or the VSS (vehicle speed sensor) is faulty and going bad. I have never seen a failure mode like this, but it is the only other part short of the speedo cluster itself that has anything to do with the speedometer function. It is located on the tailshaft of the tranny. basically what it does is send the signal to the speedo and the speedo converts this signal to your gauge.

Hope it helps


06-28-2003, 01:51 PM
Is this speedo mechanical or electronic? How difficult is it to pull the speedo from the dash to inspect?

06-28-2003, 02:12 PM
The speedo is electronic, and uses no cable. It gets its signal from the VSS on the transmission. Taking is out requires removal of the instrument cluster bezel and related parts, then removal of the cluster itself. It is not very hard at all, and can be done in probably about 15 minutes or so, depending on your choice of tools.


06-28-2003, 04:16 PM
To remove the gauge cluster:

1) remove the ring between the steering wheel and the column covers - it's clipped in on the turn signal side.

2) under the lower column cover are three screws - phillips head-
remove them and the column cover - pull apart the two halves.

3) pull the headlight switch out and remove the knob.

4) gently pull the cluster trim panel off it is held o with spring clips. Behind this panel there is a connector for the auto dimming lights (if you have them) and on the right side is a tube that is screwed on. Remove both and the trim panel.

5) There are 4 - T15 torx screws that hold the cluster in. remove them and pull the cluster forward - reach behind the cluster and you will find the electrical connections - one large grey clip on either side. Push the tabs on the sides of the connectors in and pull the connectors out.
You will also need to remove the boost vacume line.

6) remove the cluster by turning it as you remove it. Once out, you can remve the top clear panel and black bezel for direct access to the gauges.

If you want to install white faces on the gauges, gently pry the needles off using a desert fork. Place something soft between the fork and the gauge face so you don't mar it. The OEM faces are glued on and with gentle persuasion, they peal off. On the tach - there are three small screws to remove before removing the face.
NOTE: Before removing the needles - note their exact position on the gause for reinstallation.

This is also a great time to do the oil gauge modification. I just wish there were gause faces for the water temp and oil pressure with numbers instead of C - H.

Good luck

'93 SC

06-28-2003, 05:35 PM
Great! Thanks for the info. One more question. If I need to replace it is there a place to get aftermarket gauges or custom faces? I keep hearing of a 140mph speedo. Can that be installed in my 92? Where can you get it? Also what is the "oil gauge modification" you mentioned?

That was one question wasn't it?;)

06-28-2003, 11:39 PM

ok - there are several places to get white face gauges or indiglo gauges - check ebay or TCCoA.

I believe earlier in this thread Mike Puckett posted a link to a speedo repair place. I know the later SC's came with a 145 speedo but I'm not sure if it's a direct swap.


check the link above for the oil pressure mod.

Have Fun,

'93 SC