1999 Dome lights flicker / relay clicks same time

I have 1999 suburban (old body style) and when the dome over ride button is out, the dome light flicker on and off with all doors closed and driving down the road or parked at a light. There is a relay noise sound under the dash that clicks the same time the inside dome lights go on and off. I had to over ride the dome lights to keep them off. Is it a faulty relay and does any know where it is and which one? Thanks for any help. Dave

Chances are that it's not the relay at all...

Door jams switches are a common problem on these trucks.

Check them all. Problem one is probably the driver's door.

Had same problem. Replaced the switch, because it started doing it once when I used the dimmer dial to turn on the lights. FIgures somehting broke. Wasted $35 on the switch, started doing it again 1 week later. I think it's the rright rear door not closing all the way now. I've been slamming it hard and it seems to take care of it.

Thanks for all the help.. I replaced my driver side door switch last month. Took a look at it again and it need to be replaced again. I filped it in and out a few times and now the lights work ok again. So back to Chevrolet for a switch again.. Dave