adrainey Report post Posted February 19, 2016 2005 Freightliner Expedition speedometer. 26,000 actual miles. Purchased motorhome used in Texas and drove back to Los Angeles. Speedometer was not accurate sometimes, then accurate at other times on the trip. Back home, Speedometer settled down for several trips including the last one to Yosemite for 300 miles each way. In Yosemite we sat in pouring rain for 2 days. Trip home, speedo seemed to be OK. Put motorhome in shop to have them set up new dish antenna and set up front and rear tvs. When I picked it up and drover it about 4 miles to the storage facility, the speedo started acting up. Calling my wife who was following me for speed check, I was traveling at 55mph and speedo showed 35. For the rest of the 4 miles, the speedo was about 30 mph low including when I pulled off the freeway and needle went below zero and circled around below guage past 6 o'clock continuing counter clockwise to the right so when I stopped it stopped to 4 o'clock position? RPM guage was and is correct. Engine ran perfectly. IN reading about such problems, had suggestions about where the sending unit was and wiring loose etc ? ? ? Anyone tell me how this thing works, where to look and maybe what could be causing it? Corrosion maybe? If so, Where? Dudley Share this post Link to post Share on other sites
wolfe10 Report post Posted February 19, 2016 Dudley, Give Freightliner Gaffney a call with your VIN for troubleshooting assistance. Freightliner 800 385-4357 Share this post Link to post Share on other sites
wildebill308 Report post Posted February 19, 2016 Dudley, Brett gave you good advise. One of the first thing I check when having any problem with dash electrical is to check the ground. Some times just cleaning and tightening the ground will fix erratic behavior. Let us know what you find out. Bill Share this post Link to post Share on other sites
garyreed Report post Posted February 19, 2016 Dudley Those are exellent ideas to start. I do have a question, Stopped in park with the engine at idle or a little above will the speedo needle bounce maybe ever so slight? If yes it could be the yoke loose on rear of transmission. If no it could be the sending unit although fairly rare. Check the plug on sending unit and any chassis ground. Also when checking and cleaning the ground as Bill suggested, don't forget to check plug going to the speedo or gauge cluster. Sometimes the weight of the harness create a loss of signal. Have you been able to tell if the odometer is counting miles correctly. This might lead to a faulty head. Gary Gary Share this post Link to post Share on other sites