On my 1989 dodge d150 it is a 6 cly.
i got the maintence req light on the dash.

What does that mean and what do i have to do to fix it?

 

Pick up a Haynes, should tell you how to reset it. Usually on old vehicles it is just run off a timer, every 60k miles or X number of hours it'll trigger the light. Just reset it after doing whatever normal maint is scheduled.

 

I had that light on my '85. All that light means is have the emissions system checked, and like the other guy said, it is triggered by a timer. All i had to do to fix mine was locate the timer unit, which i think was behind the glove box and required a 9v battery to be changed out. really simple fix.

 

I got an 89' d100 3.9 v6 i actually just printed out info on the EMR light. I got my info from MitchellOnDemand which is a database like AllData. It told me that the EMR module is under the dash to the right of the headlight switch.