Here's an odd problem I recently ran into on my 1996 854. I have 225,000 miles on the car now, its runs great, and it's always been well maintained to the schedule. I drove the car to work a few weeks ago and all was well. At the end of the day I get in the car and it starts right up but the ABS and TRACS lights are on. Then I noticed the transmission shift interlock isn't working so I had to manually override it. I stopped and restarted the car but same problem. Then I noticed the speedometer wasn't working either. I figured there's a bad fuse so I checked the manual and it says the rear window defroster and heated mirrors are also on the circuit. Sure enough, they don't work. I stop the car and check fuse #28. Its fine so I put it back in and try reseating the fuses. Restart the car and the problem is gone. Since that day I've had this problem happen 3 more times but all I had to do was stop the car, pull fuse #28, reinsert the fuse, and restart the car. Yesterday the problem happened again but the trick of pulling and reinserting fuse #28 didn't work. So I drove the car for a few miles and then next time I restarted the car the problem was gone. This seems to happen on hotter days.

Any ideas of what might be causing this problem or where to check first?

Thanks!