My cruise control stopped working two years ago. I bought a used (working) Cruise Control Control Unit (Under Passengers Seat). This did not fix the problem. I then replaced a MicroSwitch (located near the gas pedal and clutch pedal) with a new switch. This did not solve the problem. I then checked the fuse for the cruise control...but it was fine. Do you have any ideas? David Schmidt
Cruise Control Won't Engage on 1990 Porsche 911
by xena in Jacksonville, FL on February 02, 2010
ANSWER by patrick mannion on February 02, 2010
If the clutch master cylinder was ever replaced I would have guessed the pedal switch was mis-adjusted. You need a wiring diagram and an over view as to how the system works. There is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You get a one year subscription to year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual. http://bit.ly/alldata_repair_manuals or try http://bit.ly/mitchell_repair_manuals_online and get an online repair manual subscription.