I have had this S90 for about a month or so now. Everything has been working flawlessly, I took it on a trip up the east coast of FL and used the cruise control about 3/4 of the time and it worked great, then all of a sudden it quit working. I checked for a fuse in the owners manual but could not find one. Anybody have any suggestions where to start?

 

Anybody?

 

A fuse is probably not your problem. Several of the main fuses near the battery are involved with the cruise control, as are the brake light and ignition switch fuses from the interior fuse block (drivers side dash). The actual power to the cruise control module (big relay type box, on transmission tunnel behind trim panel near gas pedal) comes through fuse 19 in the interior fuse block, but from Owners Manual that fuse also supplies power to the turn signals and backup lights. So if you've lost several functions, then it might be a fuse.

Suggestions on where to look for other causes are lose of vacuum (but car would then probably run like crap) and the switch near the brake pedal not closing, which allows the cruise control to work. The steering column stalk has a small (5 wire) connector that operates the cruise control, you might try pulling that and spraying the contacts with electrical cleaner in case one of those connections is bad. You could also have a problem with speed signal from the dash getting to the cruise control module, but now you'd be into a major hassle just getting to that stuff.

If you want a scan of the two pages in the wiring diagram, contact me with email address. The attachment limits in this forum are way to small for most pdf docs.