I went the other day to Auto Zone here in OR and they said they still do the scanning but not on my '88. Too old!
they probably only do OBDII. Its easy to get the codes from an '88 though. All you have to do is run a jumper wire (paperclip) between two of the holes in the diagnostic port, and then turn the truck on, and count the flash sequence. Compare it to the code chart, and you can figure it out.
