I know this is not a V90 forum, but the 960 wagon is similar to the V90 and members may have experiences this problem. The dashboard bad bulb warning light turns on when I step on the brake pedal. The driver's brake light is weakly lit and the plastic portion of the brake bulb socket was partially melted. Does anyone have an idea why this circuit is drawing so much current that it is melting the plastic? Reseating the brake bulb in the socket fixed the bad bulb light and corrects the dim light. Thanks in advance.

 

It may be a common design problem. But make sure it has the correct bulb installed.

 

Thinking that a poor connection was the culprit with increased resistance generating head, I cleaned the connection and applied a dilectric grease. The bad bulb problem is solved. thanks

 

Your thinking is correct. Furthermore, Volvos seem to be particularly sensitive to excess heat from the 2 series through to the 9 series. Brake lamps, particularly w/ automatics, get HOT. Sitting in traffic with one's foot on the brake generates a lot of heat. Additionally, previous owners may have installed higher wattage bulbs, vainly attempting to get brighter lamps or just ignorant.

 

I have the same issue on my 240... one option is to upgrade to led bulbs. They create less heat

 

After market lights seems less tolerant to heat. But I have seen both kinds with melted plastic, usually at the brake bulb, logical since many drivers ride the brakes. Sometimes housings are fixable with a grinder, getting the holes back to the right shape.