No speedo

[dan brooks]

In the past day or two, my speedo has become tempermental. If the truck sits for any period of time, the speedo won't register for a few blocks or until I tap the dash, then it works fine until I shut the truck down again. The odometer seems to work okay. I checked the grounds, connector and speed sensor but the problem is still there.



I'm leaving for Oregon in a few days and don't need to have problems on the road - any ideas what may be causing this?

 

[DValentine]

Dan, I had similar problems last summer- drove me crazy.



I can't remember exactly what the part is called. But it resides right off of the transmission ( not sure on the auto, as I have a manual) and converts the mechanical motion to electronic signals. So one side unscrews from the speed output and the other half unplugs from the wire harnes. I may be all wet here with the auto as I have not wrenched on one but I think the parts are the same. Please excuse if my foot enters my mouth.



Dave

 

[dan brooks]

Thanks, Dave - I think you're talking about the VSS (vehicle speed sensor), AKA "distance sensor. " I've had intermittent problems with it over the past year or so, but removing it and shooting some contact cleaner inside has always fixed it before - no luck this time. I went ahead and replaced it a little while ago just to rule it out as the culprit.



Strange thing is, when I took it for a ride this morning - before swapping the sensor - it worked okay. Hopefully this is one of those "self-healing" problems that will never come back.



Did your speedo and odometer stop, or just one of them? That is what has me confused - the odometer seems to work okay even when the speedo doesn't. That, and the fact that tapping the dash will bring it back to life has me concerned that it's the speedo itself... .

 

[RottenRon]

Same thing happens to mine every once in a while (maybe once a month or so). I just tap the speedo and presto... I don't really like this work around solution however I think the correct permanent solution is to take out the speedo and then take it apart to clean the little speedometer needle base motor. I'm not even sure it comes apart, probably doesn't. I saw that the odometer works, so the signal is getting to the speedo - just seems like something I could live with. Interestingly, when it first started happening I would just continue to drive until it sprang back from zero by itself after a few miles; it took my wife driving the truck once and saying "I had to tap on the speedometer to get it working" to realize I could get it to work that way. So sometimes it is OK to let the wife drive the truck!

 

[dan brooks]

Thanks, Ron - I feel better knowing yours has been doing it for a while and hasn't quit altogether. I was really worried about it dying half way between Arizona and Oregon. There is a good speedo shop here in town, and once I get back I may just let them mess with it... I'd hate to screw it up and lose my low original mileage.



I guess of the two I'd rather have the odometer still working - I can judge my speed better than I can my distance.