Is the system not called OBD2? lol (On Board Diagnostics 2)

 

No my trucks an 89 obdII didnt start till 96. pre obdII chryslers were drbII which is what youre truck has since its a 93

 

Pre 92 is drb2. 92-up is OBD1. 96-up OBD2

 

the 89 does not have a obd 2 system. it is obd 1 and the connector is located on the firewall, upper right hand passenger side. it only comes on once for maintenance. it's not like the 92-96 where it comes on for every maintenance issue. find someone with an obd 1 to plug in and turn it off. i've read about that reset box but i'm not sure if the 89 had one.
i removed the bulb, problem solved.
have you done the key turn to see if it's another code thats causing the light to come on?
think they have the procedure in the FAQ section above.
yes it is "on board diagnostics" or OBD.