To check for trouble codes ground port B with the ignition on but the engine off ( connect A and B with the key forward) and the engine will flash a series of codes, first and last of which sould be 12. Each code will be two numbers slashed separately. 12 will be one flash, a pause, then two more flashes, then a pause and it will move on to the next code. Once you've recorded the trouble codes you can check them at the bottom of the page here: https://www.thirdgen.org/newdesign/faq/thirdgen.shtml

 

Here is a pic of the ALDL that you want to use to read the codes. It will be underneath your steering column to the right, you can use a paper clip or a piece of wire to read the codes. Sorry, this was meant to be a reply to your old post, not a new one. Oh well.