After checking all outside lights (rear running, brake lights, back up lights, side marker lights, front lights, parking lights, rear fog lights, etc), they appear to be all functioning properly but the dash Bulb Failure Light still comes on whenever the brake pedal is pressed. Any clues as how to eliminate this problem will be appreciated.

One of the bulb pairs is drawing enough more current than it's sibling to cause the light to go on.

You may be able to detect a bulb drawing excess current by the dark deposit on the glass although such deposit may not be visible. Often replacing the bulb with a darkened envelope precludes the failure of the bulb although the one you put in may die an infant failure.

I've had some luck with brake light problems by replacing them with the genuine volvo bulbs. Don't ask me why, they seem to keep the bulb failure unit happy.

Someone told me a couple of years ago...and it may have been in here...that it is important to have ALL the same bulbs installed. In other words, do not mix OEM bulbs with aftermarket. The brass base on aftermarket bulbs and the nickel base(or whatever they are) Volvo bulbs conduct the current slightly different and this is enough to trip the sensor. Don't know if it is true but I don't mix bulbs anymore and I don't have the problem any more.

A side thought.

While you have the sockets out of the Circuit Board you might want to melt solder onto the bare copper of the circuit board. The copper is very thin on the circuit board screwing in the sockets beats that copper up pretty good, a layer of solder helps the longevity of these rear light circuit boards.
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'75 Jeep CJ5 345Hp ChevyPwr and two motorcycles: it wasn't Volvos safety , it was Longevity that sold me

Try replacing both brake light bulbs with brand new ones, make certain there's no water accumulation in the taillights, and clean off the 3 tabs on the bulb socket with fine sandpaper or a nailfile. Eliminate corrosion in the system.
Make sure the ground screw is clean too.
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Rob Bareiss, New London CT ::: '87 244DL/M47- 221K, 88 744GLE- 202K, 91 244 181K, 88 244GL 145K

Just had this on mine. The three tabs/contact points has dirt/corrusion on them. Right brake side if I remember correctly..

I am experiencing this problem right now with my 99 S70 GLT. Been to the dealer at least 3times and they keep changing bulbs at my expense and the problem re-appears even before I get 2KM from the dealership, instead of diagnosing the problem properly they seem to be guessing. This is so irritating that I have just threatened to go elsewhere for servicing.

Welcome to the wonderful world of Volvo Factory Service!! :)

http://www.alldata.com/TSB/64/99646065.html


IIRC that year FWD had problems with the weird lightbulbs/plastic bits on the bulb AND the socket. Essentially not enough contact to handle the current so it gets hot. I understand there is an alternative bulb with a ceramic bit on it.