My Yukon has a "Click"ing (of all things) sound under the dash where the hazard relay is located. I replaced the relay, but it continues. At random, however, it may stop regardless of road conditions (rough or smooth), then start again. Last night apparently it began clicking and killed the battery. I began relooking into this, before recharging the battery, when I discovered that clicking, while the vehicle is turned off, will stop when the brake is pushed, then starts again shortly after. I cannot feel any vibration (click) on the relay switch. Pulling the relay switch has no effect and it keeps clicking. After charging and restarting the vehicle, the clicking continues regardless of the brake being pushed, but I feel the vibrating on the relay switch and when I pull the relay switch it stops…now what do I do?
If the vehicle has an alarm system try unlocking the doors using the keyfob to see if that makes any change when the trouble is occuring. If it does the alarm system may have some trouble. Another thought, the trouble could be just with the flasher unit and replacing it will solve the trouble. There may a technical service bulletin (TSB) out for this problem so check into that also.