Originally posted by WANT '71 280SEL
To replace the sensor in the bumper, does the whole cord have to be replaced? If so, where is that long wire routed through, my dad's 300E just has a blank display.
First, the answer is no, you don't have to replace the entire cable, you can just replace the thermistor at the tip (do a search out "outside temp"). Save yourself the trouble, trace the cable to the fuse box where there is a connector underneath the fuses - I believe the wires are green and brown. Connect a 3k ohm resistor (get at radioshack) to the end that goes back to the cluster and you should get a reading. If you don't, the problem is somewhere else...