TJs98GT

i have a DM speedcal that has been on my auto, my t45 and now on my tko. it worked fine with the auto and the t45 and then i hooked it up to the tko and it read 150 when i was in third going about 40, so i disconnected it for the time being to see if i needed to change the settings. i had it plugged into the sensor on the right side which looked to be an electrical speedo sending unit and my others were mechanical. the setting was on the proper one so i tried to hook it back up and it didnt work. i checked the fuse for the cig lighter where it was plugged in and it was blown. i replaced the fuse and it still didnt work. is it possible that maybe i fried the circuit board? i dont have the cigg lighter hooked up because i never had a use for it, but i checked it with a test light and there is power getting to it.

so next i took the mechanical speedo sender from one of the old transmissions and put it into the TKO and hooked that up and it still didnt work. so im shot out of ideas. the only thing i can think is whatever happened when that fuse blew that it might of messed up the speedcal but before i go and spend $100 on another one i wanna make sure thats the not the issue. let me know what you guys think. thanks!