so i put a sunpro tac in my truck and it said to taping the brown and yellow striped wire to get rpms. i did it it worked fone for over 6months the other day say when im in 4 gear at 2000rpms now its only reading like 500rpm and when i rev it up it normaly is 4500 to 5000 rpm its only 2000 rpms any ideas

 

i'm guessing a bad connection. go back and check your connections.