Cadillac Repair: 1994 Cadillac Seville Cruise Control, neutral safety switch, cadillac seville

Question
The Cruise "light" comes on the dashboard when it is activated, indicating cruise is "on".....but it does not work!  Any ideas would help!   I also have a 1991 Deville that gives a "Service soon" light, but the error code is for "park/neutral switch".   This also keeps the crusie on THAT car from operating as well.  This situation is sometimes clear, indicating no problem!  It comes and goes.

Thank you for any help you can provide.  

Answer
Hi Robert, Lets start with the easy one...'91 DeVille. If you have the E091 that is setting then there are 2 possabilities. The first is that the switch is out of adjustment because the shifter has been moved before the brake pedal has been pushed. Otherwise there was a service bulletin published probably back in the '91-'92 area that calls for a redesigned neutral safety switch to be installed because some of them had problems early on. That might be a dealer only part but a few calls the the parts stores in your area might show that they sell them also.

    As for your '94 Seville my first thoughts are that the cruise control brake switch...the one with the vacuum hose going to it above the brake pedal...is leaking and not able to hold vacuum. You could try removeing the hose and plug it. Then go for a drive and if the cruise now engages then replace the switch. You will need to turn the cruise control off by the switch on the dash because since you have the vacuum hose plugged it can't turn off the cruise by pushing on the brake. Since the light turns on to indicate the cruise should be on when you push the set button then the turn signal lever switches and fuse should be funtional. Sometimes the cruise control servo under the hood can develope a leak in the diaphram or its internal solinoid and can't hold vacuum. There are tests that can be done to determine if the servo is bad but you will need a shop manual to perform the tests. I know this sounds crazy but you did check that the rod is hooked up to the cruise servo and the throttle lever under the hood right?

     Let me know if you need anymore help. Bill