As I work through items refurbishing this coach, I am getting into some second tier things that weren't working. I concentrated on the "creature comforts" AC, heaters, water heater etc. first and now I am on the VDO speedometer. According to the PO, the original speedometer failed some time ago and he bought a new VDO and had installed by a less than skilled mechanic. It never worked and I just have been using my Garmin for speed control. The speedo self tests OK and I have zeroed in on a signal problem. After talking to Lauderdale Speedometer (Jay), he recommended abandoning the transmission driven sender and going with a GPS sender. Easy setup; dash mounted unit and no wiring hassles. This wires directly to the lugs on VDO speedometer. Has anyone installed one of these yet?
VDO GPS Speed Sender | VDO Instruments and Accessories (https://www.vdo-gauges.com/vdo-gps-speed-sender-enthusiast)
jk
I have not done the GPS route, but I have rebuilt the original sender and drive pins. If you care to keep it original, Steve @ Speedometer Service in Scappoose Ore. is a great contact person for any parts you may need. (503 227 7768). The cruise control sender T's off of the drive unit for the speedo sender and it was froze up on our rig which caused the drive pin to sheer. I removed the cruise control sender and replaced the drive pin and all is well now. I went this way just to keep things original. Going the GPS way may take out your cruise control, which would be OK if you don't use it anyway. Your cruise control may still be OK even if the speedo sender is bad. Have a great day ---- Fritz