Today at work I found that 3 wire plug near the booster.The black wire has continuity to ground,The red wire has batt voltage & the yellow wire has 1.98v on low speed & when the high speed button is pressed it has9.82v.I would think now I have a blower motor resistor gone bad but in my experience on other makes of vehicles when the resistor goes south you have one speed only,high.When you try low the blower stops & you have no blower at all.Maybe its a MB thing.What do you think?Thanks.