T/S envoy speedometer

[aztortuga]

I am having periodic problems with the speedometer in my MH, a 2005 Spartan MM chassis. The speedometer will not work when I first start and move the MH but it will come to life after 10-20 minutes. Then the next day the same refusal to work at startup. Spartan thinks it may be the speedometer itself. Spartan has them in stock new for $475 but I hate to buy unless I am sure the speedo itself is the problem. Anyone know who makes these speedometers? My Caterpillar pocket Tec reads the electonic data fine at the dash board service plug so the data is getting to the dashboard area, but the speedo itself seems to either not be getting the info or is malfunctioning itself. Man these electronic glitches are troublesome.