Tahoe Dome Lights

installed a overhead video mnitor with Dome Lites in 2007 Tahoe and the Monitor has Negative Dome Lite Input.  The Tahoe has Positive Dome Lights, but they fade or dimm out.  I put Relay in and the Relay buzzes when the lites start to fade out.  The Relay stops buzzing when the Dome lites go to 0 volts.I have had this problem before in other Tahoes, & just never hooked up Dome Light.Any HELP would be appreciated.

Use a capacitor and diode on the relay to stop this. A small cap of about 1,000 uf should do. Install it across the relay coil and install the diode inline in the positive input to the relay coil before the cap and with the band facing the relay. This configuration will allow the relay to de-engerize properly.sparky