I have a '92 740T, and have been struggling trying to fix my cruise control. I've read the FAQ, and tried many of the things it suggested, save taking apart my dash to find wiring shorts.

The symptoms:
-O/D-off button only works when car is in Park. As soon as the car is put in drive, the O/D cannot be disengaged.
-Cruise control completely inoperative.

I've done the following, and had no luck:
-checked all vacuum lines for leaks. OK
-checked stop light switch. OK
-checked vacuum switch at brake pedal. OK
-checked fuses. OK
-swapped vacuum pump with other car. OK
-swapped O/D relay. OK
-swapped bulb failure relay. OK

I plan to continue to trace the cruise control circuit looking for shorts or breaks, but I'm suspicious that the O/D problem and cruise problem are related. Has anyone else ever seen a problem like this? Any suggestions?? thanks.

Kevin.

A follow up to this post. I got under the knee bolster/kick panel area this weekend to inspect the wiring, and everything looked OK. I wanted to test voltages at the different terminals of the cruise control module, but the color and number of wires was different than what my slightly out of date manual told me. I'd like to make sure the control module is working OK, and I have an '86 740 that I could swap with. Are the '92 and '86 cruise control modules the same? I wouldn't want to fry anything by swapping the modules. Thanks.