Truck wont shift into OD or 1st gear

[Next GenRacing]

Hello, I bought my truck about 6 months ago, and am now starting to drive it cause of the cold weather. When I purchased the truck it wouldnt shift gears automatically, and only has 2, 3 gear, no OD or 1 gear. The guy I bought it from said he thought it was the plug on the top of the tranny, because it was missing some pins (broke off trying to clean it or something). would that cause the truck to not go into 1st or OD at all? Or should I be able to manually put the lever into 1st gear and get it? If this is potentially the problem what part do i need to buy exacty to replace it and roughly what kind of cost am i looking at?

Thanks
Danny

[ipz2222]

With no power to the trans, it goes into 3rd gear. Pulling the lever to low gives you 2nd, moveing it to 2nd , it stays in 2nd, moveing it to 3rd gives you 3rd. Trans must have all the connections working.