Here you have it, 1990 Dodge Dakota wiring diagrams (PDF, 5.6MB).
I'll eventually post the wiring diagrams for the 1996 model year (gotta scan the suckers first).
I also have the rest of the 1990 service manual, and the 1996 (of course I would, I do own that year ), so if you need anything out of there, just ask.
And, I plan on aquiring other years service manuals via eBay, so I'll update when I get "new" ones.

 

COOL, I have a 95 Dak sport, 3.9 2wheel drive and my Chilton's manual doesn't show wiring for interior lights or radio/speaker. Oddly enough I have an issue with both, can you help me?

 

What is the problems you are having with them? For the most part, the wiring for those systems isn't really differant between 1990 and 1996 (I know you said yours is a '95, while I don't have a '95 wiring diagram, I can draw conclusions from the fact that 1990 and 1996 are pretty similar). The main differances is what fuses those item's use in the cab, and around 1993 (I think, not sure) they added the Power Distribution Center (PDC), which is the black box in the engine compartment that contains your relays andthe big fuses, instead of having fusable links like they had before.
The dome light (which is what I presume you mean by interior lighting), is towards the bottom ofsheet 33 (by sheet I mean, at the bottom in the corner it will say "AN 33").
If you have an extended cab, radio wiring can be found on sheet 43 and 44. For regular cab, sheets 45 and 46.

 

right on and lil friendly FYI the 92 kota also has the PDC, not sure bout 91 though

 

The problems I am having are the interior light stopped working, fuses are good but I don't know where to check wiring, no it doesn't work if i groung the wire at the switch. The other problem is the aftermarket radio that was installed fell out!! (I just bought this truck very used) I put the radio back in using the experience i gained over the 57 years i've been around, and low and behold, it works. It would still be nice to have or have access to the wiring.