Speedometer stopped working, I replaced it with used one and worked for a week or so, replaced again and still does not work. I have replaced to Sensor on the tranny and also the ECM (2 times), still no luck Was told by my electrical mechanic that the ohms in to ECM are perfect, but coming out very low. Was also told there was a Yellow Speed control box under dash, but I cannot find that so not sure what we are looking for. ANY HELP would be Appreciated.

 

THE BOX I THINK YOU ARE TALKING ABOUT IS A BUFFER. THE ELECTRICAL LINES FROM THE TRANNY FEED INTO THIS AND THEN FEED OUT TO POWER AND THE SPEEDOMETER. MINE LOOKS LIKE THE ONE IN THE PICTURE. THIS SHOULD BE LOCATED NEAR THE COMPUTER MODULE I THINK.

 

Thanks for the info , but just found out that from Chevy Dealer that the V6 doe snot have a VSS buffer only the V*....Still need help