Odometer works Speedo does not

[Mr.Papabear1]

Hello all-
Our new to us 2002 Holiday Rambler Endeavor's speedometer has decided to periodically quit working. Sometimes it works, sometimes it does not. Majority of the time it does not work. It will go as high as 15 mph and that's it when it is not working. The odometer works fine.
Could the cause be a bad sensor in the Allison transmission? Any thoughts?
Thanks

[94-Newmar]

I doubt it's a bad sensor in the transmission. The 3060 is extremely sensitive to having all 3 sensors (turbine, output shaft and input shaft speed) being correct (ask me how I know!) It would be setting a troubleshooting code on the transmission shiftpad if it were anything in the transmission itself. I assume the tachometer is working correctly? If you're able to get under the dash I suggest looking for anything loose going to the speedo and closely looking at wiring entering/exiting the vehicle interface module which serves as a "bridge" for most everything from front to rear. It could also simply be the speedo itself which has failed.

[nodine]

Originally Posted by Mr.Papabear1

Hello all-
Our new to us 2002 Holiday Rambler Endeavor's speedometer has decided to periodically quit working. Sometimes it works, sometimes it does not. Majority of the time it does not work. It will go as high as 15 mph and that's it when it is not working. The odometer works fine.
Could the cause be a bad sensor in the Allison transmission? Any thoughts?
Thanks

I suspect your speedometer is bad. I believe these are pseudo speedometers and the needle is moved by some kind of rate proportional device that converts electrical pluses into mechanical motion. We have two other devices that indicate our speed; a GPS and the Silverleaf VMSPC. I almost never look at the OEM speedometer. Suggest you get one or both of these and forget the speedometer. The mileage indicator still works but even if it didn't the Sliverleaf can show the miles from the engine.

Bob

[Libero]

I agree with Nodine. While fixing the speedometer is a good idea, I rely on my GPS as a speed indicator, albeit you must obviously have GPS reception for this to work and there is some latency in GPS reporting but I have found it is more accurate than my speedometer.

The device that changes the energy form for the electronic speedometer display is called a transducer.

[MandG-Fun]

I'll third that... my speedo is all over the place, it can be 20 MPH fast one minute and 20 slow the next. I just relied on my GPS for speed, which is super accurate. Then the fuel gauge started to act up. Nodine's recommendation of a Silverleaf VMSpc was my solution to the uncertainty of the situation and my concern that fixing the speedo and fuel gauge may be temporary and expensive. The side benefit was great, the Silverleaf provides so much information it can actually modify your driving style and save enough in fuel to pay for the whole setup in no time.

[scubastevee]

Hi,

if you can get at the dashboard circuitry, check for any cold solder joints. I had the opposite problem of the speedometer working but not the tachometer ... removed, the dashboard and circuit board and found a lot of bad solder joints.

Solder joints should be shiny, not dull and no cracks. You may find that loose connection goes to a bad solder joint on the board too.

[ahicks]

A speedo acting like that would simply make me crazy. I would have to fix it or replace it. A factor here though may be the fact I do all my own repair work and have no fear regarding electrical stuff? Likely makes me a little more anal about stuff like that?

I agree with the comment above. If the odometer is working and the trans is shifting OK, logic would say the speed sensors are OK (I learned that the hard way too!). This would lead me to the instrument cluster, seeking knowledge regarding the signal source for odometer and the speedo, to see if/confirm they are the same? From there it gets more detailed, but basically, with the fact the speedo is partially functional, I'd be looking for bad connections of some sort. Could be a card edge connector, a cold solder joint, etc. I don't think I'd want to pay somebody to do that though? I'd just replace the speedo head. -Al

[nomad1ne]

I have a 2004 Class A Four Winds Hurricane Ford Chassis changed the battery a few months ago and just now took it out to fill the gas tank and noticed the speedometer not working, but the odometer and Cruise control is OK. is there a reset or something???