1998 Plymouth Neon Speedometer only works after hitting the

Electrical problem
1998 Plymouth Neon 4 cyl Front Wheel Drive 115000 miles

Please help it is driving me crazy I have a long trip to go on and the speedo was replaced about a year ago the speed sensor about 6 months ago. The speedo goes out after hitting a bump or just while driving on the throughway or any time at all. If I hit the the instruments the speedo begins to work. What the heck could this be. My friend has cancer and I am making a long trip to see if I can help her and I am nervous I will have a problem with this. SOS. Thank you so much. I just hope I don't have to take the dash out to get to it since I don't see any screws to get to the cluster! Thanks sooooo much.