No harness??? There's 3 wires ground power and the other one. Wire the black one up to a ground source. On your car theres a metal piece that bent upwards inther the sttering wheel. Screw it onto there to ground it. (It's not the best ground but it'll do for this little gauge) Wire the gauge to a power source with a switch so they're not always on or an accesory power source (Afktermarket decks have em ont he back). Go to the ECU. Passenger side, near where your foot would be. Take off th paneling and hook it up to the big white wire. Then giver er a test and conceal the wires
Dont test the cr if the cu isnt connected lol.
