Quick question: Some months ago I replaced a burnt out license plate bulb. Soon after that I noticed that the bulb failure light on the dash would come on for the first few minutes after starting the car. The indicator would flicker while the car idled and when I drove away. It would turn off as soon as I applied the brakes. I did a walk-around and checked all the bulbs. All lights were functioning properly. As time went on, the bulb failure light stayed on longer. I know that the failure light comes on when the left and right hand side circuits are not balanced. So there is an imbalance somewhere. I changed the other license plate bulb just in case but I don't think that those bulbs are part of the failure detection circuits. No change in symptoms. In fact, over the past week or so, the failure light stays on all the time. Today I took out EVERY bulb, inspected it, cleaned it, applied some contact grease and re-installed it. No change. I expected to find a partially corroded connection. Nope, every socket and bulb looked pristine.

Anyone have any ideas what to do next, short of replacing every bulb with a new one? I should have measured the resistance of every bulb while I had them out but it never occured to me at the time.

I suspect a flakey ground somewhere. Or perhaps the failure relay is faulty. Maybe one of the coils is gone in it or the reed switch has failed closed.

All the lights are working correctly.

Bill
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Volvo Info Site 1990 745GLE 16valve