Hi guys,

My 1984 240 Estate has been giving me grief with the bulb failure coming on when applying the brakes. When checked whilst parked it's the driver's side lamp, I've tried numerous fixes (bending tabs on bulb holder for better contact, swapping out globes, taking the power feed from the "good side" with new cabling and connectors in case there were breaks inside the sheathing etc etc) Took off the cluster today to see if there was anything visually wrong anywhere as these are (quality) aftermarket units I put on a year or two back but zilch. I just did a quick search online and there is mention of the 'brake light relay' failing and causing intermittent faults, has anyone got any clue, it's driving me nuts! Thanks...

Wiring.

I spent weekends fixing stupidly crap light fittings and wires , nearly rear ended on dark country roads, resorted to a torch inside the tail light assembly so I had some safety but in the end getting it rewired is the key. Run a wire from brake pedal switch directly to the globes. Save a million headaches .

Thanks Snoopy, yes the long and winding road to electrical heaven is seldom paved with 240's! Frustrating thing is that after considerable faffing I have both globes illuminating now but the bulb failure light still comes on every time I use the brake pedal, just to clarify I don't mean the "brake failure" warning light for anyone reading this, I mean the "bulb failure" light. Only thing I can think of is that the actual bulb failure relay is faulty, I keep hearing that you should fit identical bulbs from the same manufacturer to sort it out, might give that a whirl, still frustrating...

Mismatched bulbs can definitely be a problem. Replacing bulbs in pairs is usually the go.

Ensuring bulbs are correct wattage is also important too.

Cleaning up the contacts on your pins and connectors can help too.

Good luck!

You could always just pull the bulb failure light in your cluster if you cbf?

Ah, an '84 - from The Era Of Biodegradable Wiring. I'd be checking the loom for chafing and broken insulation, particularly in the cargo area where the loom passes into the back seat.

As Odin said, mismatched globes and high-resistance globe sockets are a problem. As is corrosion of the ground wire and connection point for the tail lights on that side.

Look also at the fuse box. Although if your interior light is working without hassles, so are the brake lights; they get juice from the same circuit.

Do you have / did you once have a tow bar? If so, I'd be checking the connections where the installer tapped into the brake light bus, or what was done with the plug wiring when the tow bar was removed.

Excellent points @OdinsRedblock and @Major Ledfoot, I'll be double-checking that the bulbs match exactly (Narva from the same twin pack). I've gone over the globe holders and contact points meticulously, pulled the trailer connector and cleaned that thoroughly, not that it was dirty/corroded but just to eliminate it. I took the wire feeding the passenger side brake light that appears sound, just before the spade connector, and spliced in a new section of wire with solder and shrink-wrap and insulated connector to the dodgy light. I had checked the fuse which appears OK but will also check the interior lights as I've had them turned off whilst leaving doors and tailgate open to work on things.

I replaced the engine wiring harness plus the ignition harness with ones from Elbert Bos in the Netherlands a couple of years ago so I'm well acquainted with the biodegradable wiring phenomenon ?. Anyhoo I'll report back after another crack at it today...

Seems to be common , every old Volvo I've ever been in had the bulb out glowing. Old wiring/earth's.

That's interesting Snoopy, I guess the sleuth in my won't give up that easily, I've just popped out the bulb failure sensor

Locking tab snapped off but no big deal, has anyone popped one of these babies open before? I don't want to completely butcher it but I'm guessing that the plastic is pretty brittle after nearly forty years. I've done my fair share of resoldering dry solder joins on the instrument panel and relays etc so I'm hoping that having a rummage around in there might achieve a result...

Can you get specs from Green Books and test via the pins?

Good point Snoopy, I haven't got any testing gear other than a continuity probe/light unfortunately, which I'm guessing isn't going to be much help. Might try easing a small flat blade screwdriver around the lip whilst applying (judiciously) some heat to soften the plastic a bit, I've got one of those Bosch jobbies with the digital readout so I can keep it low and slow...

Here's what I found:

No "reed switches" which must relate to later models just the two coils within the structure, I redid most of the solder connections just in case there was a connectivity issue but overall there wasn't much that I could see that would affect the outcome regarding my issue ?️. I'm going to superglue the cover back on and give up on that front as there was no change - the bulb failure light still comes on when hitting the brake pedal, other thing that's been mildly bothering me is that there are a number of dash lights that pulse when the indicators are used (both sides), poor earth somewhere or flashpot?

Interesting! This thread brought memories when I had a similar problem on 245 many moons ago. Finally I ran an earth wire from the screw that holds the tail light assembly and soldered it to every bulb holder in the assembly. I fixed the same problem in the 360 too. Seems to be a Volvo design problem.

Recently, bulbs were not working although the meter showed all ok. These bulbs were recently replaced and were loose in the sockets. Problem:- new bulbs have a smaller base diameter and require packing to make them tight in the holder.

Also I was pulled over by the cops who claimed that ALL the rear lights were flashing. I could hear the flasher can quietly ticking. The hazard switch contacts needed cleaning and that lighting stunt was fixed.

    Last post, finally nutted it out, when I hooked a new wire up directly from the "good" passenger-side brake wire to the driver-side I just folded over and shrink wrapped the wire end and tucked it away as I now had a good connection with both globes lighting up. Obviously the bulb sensor didn't have the feedback to tell it all was well and responded with "bulb failure". Tapped the various hot connections together again and bingo no more warning light - happy but embarrassed camper?...

    Laurie

    Interesting! This thread brought memories when I had a similar problem on 245 many moons ago. Finally I ran an earth wire from the screw that holds the tail light assembly and soldered it to every bulb holder in the assembly. I fixed the same problem in the 360 too. Seems to be a Volvo design problem.

    Recently, bulbs were not working although the meter showed all ok. These bulbs were recently replaced and were loose in the sockets. Problem:- new bulbs have a smaller base diameter and require packing to make them tight in the holder.

    Also I was pulled over by the cops who claimed that ALL the rear lights were flashing. I could hear the flasher can quietly ticking. The hazard switch contacts needed cleaning and that lighting stunt was fixed.

    I had already run new earth wires on both sides to a fresh spot on the bodywork when I installed the new aftermarket tailights, star washers to bite into the metal and Duragal over the lot to cut down on corrosion so I was satisfied that it wasn't a poor earth but having said that I still have the indicator pulsing the dash lights issue, damn I hate auto electrics!

      Cut thoes white scotch locks out IMMEDIATELY LOL and solder thoes wires as they will cause you sorts of chaos problems

      YES. They are horrible things and will cause you more pain then there worth. I have cut out hundreds of them causing all sorts of problems. All connections should be soldered and heat shrinked or at least taped if you can't heat shrink.

      They are poor connections they invite corrosion in won't help any of your problems. Trust me I hate auto Electrics too that's why I have been an Auto Electrician for the past 15 years ?

      Thanks Lloydy for convincing me to swap out the wire taps(youngest son had left a pack behind before leaving for Melbourne and I grabbed them as a quick fix). I haven't used them before and don't intend to again....

      I don't like them for aesthetic reasons but I dunno I see plenty of 240s where they've been used to splice in trailer lighting harness and they seem to work fine.

      I was going to ask if when your driver's brake light was out, did you put a multimeter to the wire to confirm there was no voltage?

      © 2013-2023 Oz Volvo. All rights reserved. | Forum Rules | Privacy Policy