After sitting for a few months. (battery was disconnected atfer it died) Anyway, it clicks. And the speedo goes crazy when i hook a battery charger on it. Anyone every had this problem before?

 

My 99 pickup did that when it had a broken battery terminal. What it amounted to was a poor connection to the battery not allowing enough current. In your case, be sure the battery can supply enough current by having it tested. Then check all the connections. Including those at the battery, the positive cluster and ground terminal on the fender and the 2 grounds on the frame and the engine. Be sure they are clean and shiney.