Been a long while since I have been on here but her goes nothing.
Our '98 DP (SVB3862) on a Spartan chassis has a set of VDO gauges. The speedo was replaced when we bought the coach and came with a statement of original mileage from the dealer.
Initially, we were told that it is common for the electronic units to fail and replacement is the only option. If I couldn't take mine out to a speedo shop for verification and repairs, I guess I would replace it.
I will caution you that if it is electronic, you will need to program its calibration settings. This involves entering the program mode of the speedo and setting the parameters which is a "number" derived from a combination of factors (tire circumference, rear differential ratio and some transmission gear ratio). I got the info from VDO and my speedo works great now.
Somewhere on IRV2 is a post where I describe how to do this but I can't find it at the present time.
Per the prior posts, check your fuse(s), check that you have power with the ign. key "on" to your gauge/speedo. My VDO does a sweep of the needle (twice) when I turn the key on.
Linear Mode
