1997 SL2 Cruise Control Problem

I just got a 1997 SL2 with a 5 speed manual. The cruise works only sometimes. When it does work, most of the time it wont stay on longer than 30 seconds. Sometimes it'll stay on for 2o minutes. The light on the switch is always on unless i put it off myself. I took the switch apart and cleaned the contacts but that made no difference at all. I also held up on the brake pedal to see if that would make a difference but it didnt and my brake lights dont come on for nothing anyway cause i had a friend check that out behind me. Also it doesnt go into resume after it shuts off. I have to reset it like it was totally shut off and not only disengaged, (and you would be able to resume). It does have the wrong size tires on it though. Could that make enough of a difference for it not to work right? My speedo is off when i compared it to another vehicle which i know is right on. It has 205 60 15's on it and its suppose to be 185 65 15. I went to www.4lo.com (http://www.4lo.com) to compare the heights and the 205 60's are 24.7" and the stock size of 185 65 is 24.5". Any suggestions would be great. Thanks.

I would suggest checking the brake switch. It sounds as if its being hit and shutting the cruise off. You can also check the connections going to the servo that moves the accelerator pedal. Again make sure they are clean and have good contacts.

And the size tires you have on it wont have any effect on the cruise control, except maybe to raise the minimum speed at which it will 'engage' by one or 2 mph.