Wiring help please

[matt blowen]

Hi peeps ive got a glowshift boost gauge with earth, constant an swithed live, problem is when i switch my headlights on the gauge goes off? I have wired the contant to the cig lighter and the switched live to the yellow and black wire under the relays below to steering wheel, whats the problem? Thanks in advance

 

[matt blowen]

All sorted, changed the earth point now works a treat, i would post a pic but they dont upload very good, 5* for the gauge tho, very good quality and works very well 😀