Both back-up lights on my 240 stopped working. I checked bulbs, ground, wiring, plug into circuit board of lights and all lights work except back-ups. I put my test light to the yellow wire to the switch that's on the 'automatic' shift lever and the starter engaged --oops! What are the colors of the back-up light switch and how can I check for 12V of power to the switch at the shifter? Is there a fuse for the back-up lights at the main fuse block on the driver side? All fuses are good. Nothing is noted on the label in the fuse cover or in my Haines manual.
Any suggestions on how to troubleshoot this is appreciated.
Oddly enough, I am car-sitting my Mom's '92 240 for the week and noticed her back-up lights don't wok either. I'll take it one car at a time, but is this a common trait for this model?
Thanks in advance.
Marc
'93 240 126K, '92 240 110K, '90 240 94K, '78 245 256K

Pretty common for the reverse light switch to get out of adjustment as the bushings in the shift linkage, and the engine mounts, start to wear out. The shift lever and switch are on the body, the actual linkage is hard-mounted on the trans- when things move, the switch gets out of line with the contacts.

Make sure your 3 engine/transmission mounts are good, and the shift linkage doesn't have much play in it, then you can loosen the screws on the switch down in the shifter and line it back up. I'd bet the reverse lights can be made to blink if you wiggle the shifter back and forth with the button held down.

My 86 the lights blink on and off as I back up- the engine moves just enough apparently to pull the lever in and out of contact depending on how much torque is on it.
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE: 625K total

Turns out there was power to the reverse switch. Traced to the harness in the trunk. There was power going into the driver side lights. Turns out there was insufficient contact between the clip for the reverse light and the circuit board. Cleaned it, closed the gap on the clip so it would bite better and PRESTO !! - - both back up lights lit up! That took about 30 minutes. Went to the other 240 which had no backup lights and went straight for the same clip. Got them working and everything put back together in about 10 minutes.
Lesson learned; the clips to the cicuit board get to the point where they won't carry a current.
Thanks for your input!