my father currently ownes a 1990 Accord EX auto with 102k on it. The last year or so the speed ometer at times stops operating while I see a flashing S on the dash. At times the speed ometer will start working again whikle the S still flashes. Has anyone had this problem? I'm curious to what it could be so I might fix this for him. Thanks

Probably a bad speed sensor located near the firewall on the right side attached to the transmission. This problem has been discussed many times on this forum. Do a search and you will find links to pictures and replacement procedures.