ok so ive had this tach installed for a while. ever since ive had it, the light has been burned out. well i just recently got a new bulb for it and niticed it was REALLY dim. so i started playing with the dimmer. and when i turn the dimmer to to brighten, the dash lights brighten, but the light on the tach gets dimmer, and vice versa, when i dim the lights, the dash dims, and the tach brightens. WTF is going on here? when i wired the illumination light up on the tach, there were 2 wires for the dash lights. did i hook it up to the wrong wire? is that the cause of this?