Speedo not working..

[jimster502]

I was going back home and as I looked at the cluster to check my speed, I saw that it remained at zero! I was a bit nervous since it was about a 45 minute drive back home and not being able to be going the legal speed limit. I pulled over in a parking lot and checked all the fuses relating to the instrument cluster and they were all fine, none were burned. So I headed home w/ the speedometer at 0 all the way. I have no idea whats wrong with it. All the other gauges work except the speedometer. Does anyone have any idea what can it be? I'm going the pull out the cluster once it stops raining to see if its a loose cable or something...:thumbdwn:

 

[jimster502]

Removed cluster and all cables were connected properly. All the cables seem fine & dont seem cut or damaged..

 

[wicsmith1997]

My Speedometer went nuts once bouncing around and it turned out being the gear in the Transmission. I removed and oiled it then re installed and worked good. Maybe check that before pulling the cluster again. Make sure its not bound up or stripped.

 

[yavapaires]

I would go with a stripped drive gear in the transmission/ transfer case tailshaft. Or maybe it just came loose.

 

[bobflood]

I was going back home and as I looked at the cluster to check my speed, I saw that it remained at zero! I was a bit nervous since it was about a 45 minute drive back home and not being able to be going the legal speed limit. I pulled over in a parking lot and checked all the fuses relating to the instrument cluster and they were all fine, none were burned. So I headed home w/ the speedometer at 0 all the way. I have no idea whats wrong with it. All the other gauges work except the speedometer. Does anyone have any idea what can it be? I'm going the pull out the cluster once it stops raining to see if its a loose cable or something...:thumbdwn:

There is no speedometer "cable" like the old days; the speedo is driven electronicaly thru the PCM and off the Vehicle Speed Sensor in the transmission. I am not sure exactly where it is (though it should be near the tail end of the tranny). Looks like a single grey/black wire connected to it per the wiring diagram. Think this is first place to look. Good luck and report back what you find.

PS: You can estimate your cruising speed off the tach in the meantime. For my 97 5.0 EB, 70 MPH is about 2300RPM when cruising with OD on.

 

[Joe Dirt]

Most likely a bad worm gear in the speedo head, fairly common issue.

 

[drdoom]

I see he has a '97, if 4WD that has the VSS in the transfer case.

 

[ponch68]

Does your cruise control still work?

 

[baddriver]

Does the odometer work?

 

[Turdle]

If the transmission shifts fine, then the PCM is getting the speed signal. I vote for stripped out worm gear to speedometer.

 

[jimster502]

Ok, so the day after, I put the cluster back in & reconnected the battery because I was off to autozone to buy the vss, & as I left my house the cluster was working perfectly fine. I drove about 5 miles and it was working as if nothing had ever happend, but either way I bought the vss and still installed it..I have no idea what it was, but its working as if nothing ever happend to it..

 

[baddriver]

it was either the harness splice behind the i/c panel(S247??)...

or the connection between the harness and i/c panel was faulty. that can happen with the printed circuit boards on the back of the i/c.

you must have jostled it when you removed the i/c

 

[rickybobby]

my 97 did that, but a week or 2 later it quit again. My issue turned out to be a failed bearing in the t-case.