Help figuring out no speedometer

What is your question?

Hello I am new to the Volkswagen world and I am having an issue with my 04 GTI it has the 1. 8 L awp and I do not have a speedometer it started on my old transmission and I have removed that transmission due to bad synchronizers and installed a new one the transmission that's in it now came out of a Jetta 1. 8 liter and it had a working speedometer the ground on the vehicle speed sensor wiring shows that it is open the12volt power wire is good and the signal wire is only getting 0. 04 volts if anybody has some insight on what could be the issue that would be helpful!! Oh and another bit of information every time the speedometer went out before it fully went out on me it would go out whenever it was raining and it would pop the reverse light fuse I am not real big in wiring and I definitely don't know much about these cars any help would be greatly appreciated

What makes this problem better or worse?

Speedometer sometimes pulses a little bit

How long has your 2004 Volkswagen Golf had this problem?

6 months plus