and also the understanding of both Chilton and Haynes :-)
Warren, you have OBDI if your SC is '93. Yes, you can buy a code reader from your local WallyMart for under $30. I dont know how much they are in the auto store.
On OBDI if you are handy and thrifty, you can use a paperclip to span the connectors also, but I prefer the inexpensive, never fail reader. Perhaps the one you looked at had an LCD, those are more expensive. The cheap one or the paperclip will flach your SES and Temp lights in secuence to give you a code, all you gotta do is count'em and look in the accompanying book.
Mine is the Innova #3123, came with the reader and code book for all early GM models.
Hope that clears this up and you can find that reader. marx404