Wheres the obd reader for my 94 infiniti j30

Hello, pretty certain there is a light that blinks on the module itself, and a diagnostic mode must be engaged. You'll need a workshop repair manual to look into it. Keep in mind that this is not OBDII -- it's not going to be as detailed and note things such as misfires and so forth. I would focus on hands on inspection and testing more than searching for "codes" right off. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops