How do I check the engine codes on a 95 Ford Ranger?

Your vehicle may not use the OBD II diagnostic system. Auto part stores will say that they can't retrieve codes on vehicles 1995 or older because the OBD II system was very rare in 1995. It became more popular and standard in 1996 and up vehicles. Since your vehicle does have the OBD II system, the part store CAN retrieve the codes for you. Let them know that your DLC (data link connector) is located below the instrument panel, to the right of the steering wheel and that it is indeed OBD II , not OBD I. Here is a guide to help you get the codes.

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Please let us know if you need anything else to get the problem fixed.