I have a 97 ram. Long history with this but i will shorten it. Fuel pump had electrical issues so I had to put a toggle switch on it for it to run.... Then I fixed a tranny fluid leak coming from a bad o ring on the speed sensor... Now speedometer dont work, odometer dont work, and tranny goes in nuetral, reverse fine but when in D is only 3rd gear unless i manually shift to 1 and 2 but no over drive. Fluid level is fine... Please help.

 

You checked the transmission fluid level in neutral and engine running or warm, correct?

For future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

 

Keep in mind, the speed sensor is indexed. You MUST put it back in, in the same orientation it came out, or the gear will not engage the drive on the shaft. So, no speedo, PCM doesn't know what the trans is doing, or how fast you are going.... so, limp mode. Solve the speedo issue, and the others should go away.