my truck is a 90 w150 ext. cab with 318, the problem is the odometer dosen,t work. it worked when i bought the truck lasted 2000 miles then went erratic and then nothing. i tried replacing the speedo gauge and tranny sensor with no change then i replaced the entire gauge cluster board with on from another truck and the odometer started working but then quit again. any ideas on whats causing this will be appreciated
also the maintainance light is on the code is 37 but my truck dosen't have a lock up converter, could a bad pcm be the cause of this

 

Unfortunately my only advice for you is that it sounds like it may be electrical if you replaced what you said you did. I'd start tracing wires for corrossion or a loose connection somewhere. My windshield wipers worked intermittenly sometimes and other times wouldn't work at all. I have delay wipers. Rather than spending the hundred bucks on a switch i started tracing the wiring and sure enough i found a loose connection and everything works great now. I think i'm going to have to do the same thing for my oil pressure and temp gauge as they rise a little bit but never reach the point they should when the vehicle is warmed up, that is unless somebody else has some advice . I hope this helps.