Have been pulled over for the umpteenth time for brake light out, GRRRRRRRRR. Thankfully the policewomen was very nice and only gave me a $15 fixit in 30 days ticket. But GRRRRRRRRRRRR how many times have I fiddled with those STUPID light bulb holders that work for 3 days and then stop working when my attention is drawn in another direction, like accessory bushings crumbling, OH! another rant for another day......OK Vent over, reason for my post; it seems that 1157 bulbs are actually not correct, 7528 are to be used (per matthew):
https://www.matthewsvolvosite.com/forums/viewtopic.php?t=61483
and Sylvania:
https://www.sylvania-automotive.com/search?prefn1=partNumber&prefv1=7528&start=0&sz=12
Let the debated begin or did I miss something on my 1157 7528 BB search?
Also - converting to LED is not as easy as changing the bulb out, also need to add load resistors. Hmmmm worth it? Does it solve the random bulb out nightmare?
Any elegant solutions out there that don't involve re-building and re-wiring/soldering the whole assembly (saw that one, nice but before I go that route, looking for a KISS solution). I've tried cleaning the tabs, bending them, dielectric. Have not tried C4, but thinking about it. Thanks in advance!

1986 245, I am having brake light purgatory and cannot find a female plug end for the brake light switch no matter where I look. I had no brake lights, looked at the brake light switch and voila it is unplugged. Plugged it back in and nothing. Followed the red and green and red and blue wires to another connector about a foot later and that is unplugged. Red and green other end come out of fuse box I think #7 and go into thick harness by driver's door end of dash. Cannot find where they are supposed to connect to the other end to the brake switch connector at all can anyone help? Sorry don't want to hijack thread.

Incorrect bulb and bulb holder placement will cause excess heat and can melt or heat distort the plastic lens and the bulb holder mount to the tail light.

At nearly 30 years, the flex circuit board contacts, made of copper alloy in the plastic, wears. You may need new flexi circuit board. If the lens or the reflector body (usually above the bulb in the reflector chamber) is heat warped or cracked, some UV resist GOOP or the like may work, yet good condition used that works or is restorability or new is your option.




Diagram for 1986+ 240 sedan US market taillight bulb holder and bulb placement. Third, high center brake light not shown here.

As you look at the tail lights from behind your 240.


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Beh.

i stuck LED bulbs in paralell with the existing bulbs and used the unused lenses to add more light. it looks a bit odd but worked.
i used regular bulb sockets..
i tend to ignore the failure lamp.. sometimes i get the reflection of my rear lights in reflection in front of a store with glass windows and check them.
Phil

Bypass the bulb out sensor.

http://forums.turbobricks.com/showthread.php?s=dc1134a7d32fae58dc7af21f7952bfb8&t=240085

https://www.240turbo.com/volvo240mods.html#bulbfailsens1

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Beh.

Brake light problems are often at the problemetic bulb sensor, but as you describe it your problem is most likely a contact problem at the tail light assembly just as you suspect and where you have been working. If it's what I'm thinking then unfortunately it's not an uncommon problem with the 240 tail light design, especially the ones with the thin mylar-type circuit board as I believe yours has (circuit card as Volvo calls it). A couple of options for repair, including hard wiring (which most probably end up doing as it's the cheapest and most straightforward solution) and circuit board replacement (which are still available). You'll want to check out this excellent thread on the topic over on Turbobricks
240: Tail light repair (Turbobricks)

As for the 1157 bulb argument, Volvo RWDs are well known for having less than bright tail lighting, especially as the reflectors age and oxidize. Matthew's site makes a good point and has excellent tables, but good luck finding the brighter 12.0 volt 7528 bulb in any local auto parts store in North America that's a true 7528 with the lower voltage or higher wattages, leastwise in my area. Note that bulbs listed as Long Life (as many of the 7528s appear to be) generally put out less lumens. Volvo North America owners' manuals mostly specify USA (SAE) bulb numbers, like 1157 for the combined brake lights. The Volvo Pocket Data Booklet and Volvo parts schematics/fiches, which tend to be more factory oriented, reference the Volvo parts numbers and also specify the USA 1157 bulb number. These sources also give wattages specifications, which may be a bit of a mixed bag when cross referencing them to Matthew's tables. If you can find or order the brighter bulbs then great, use them.

As for using LED tail lights, as much as you might think they would be a great improvement they are generally less than a panacea. I've tried a number of the cheaper ones and been far less than impressed, always going back to the standard incandescents. The difference between the low and bright is often way too minimal to catch the attention of following drivers, which makes them unsafe. The low tail light side does tend to be a bit brighter (which is good), but illuminating the brake light side doesn't make it notably brighter (which is bad). I suspect the advertised lumens are incorrect on many of the cheaper ones. Depending on design, the amount of light hitting the reflector area and the viewing angles are also a problem. Another issue is selecting the proper LED color so that the red (or amber or clear) plastic lenses don't filter out too much of the visible wavelengths produced by the bulb, which can make them notably dimmer than on the workbench. There are better LED bulbs that others are happy with, but they are expensive. Almost all these LED bulbs should work out of the box with 12 Volts without needing an additional resistor. Even though they are low current draw, using LEDs as the two outside bulbs generally doesn't upset the bulb sensor, leastwise in my experience, as the left and right current draw remains balanced, but there are no guarantees they won't cause a problem, especially with the aftermarket KAE bulb sensor that uses all solid state circuitry. Using an LED for the 3rd brake light often can create a problem unless a resistor is added. Some bulbs come with an internal resistor to mimic the load of an incandescent, often indicated on the package. I'm sure someone will chime in with an LED bulb that they've had good success with.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Not sure if this place is legit but the price (under a buck) looks good. We’ll, OK, they’ll get you on the shipping….

https://www.newegg.com/hella-7528sb-tail-light-bulb-center-high-mount-stop-light-bulb-turn-signal-light-bulb-side-mar/p/N82E16888628098?nm_mc=KNC-MSNSearch&cm_mmc=KNC-MSNSearch-_-Exterior%2BLamps%252C%2BHardware%2Band%2BConnectors-_-Hella-_-88628098&source=region&msclkid=40a888eabe1416f5cb2de9dfa9961089

That's a very good price and the shipping isn’t bad, especially if you're buying a few. Did you notice the 4 easy payments of 14 cents? -what a laugh.

Hella is a well known and reputable brand and Newegg is a well known and reputable online source. When it says sold and shipped by Newegg (which is very much like sold and shipped by Amazon) then it's coming from one of their warehouses and you can be reasonably assured their customer support will look after any problems. Please post back for the benefit of others if you do find these notably brighter.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

“…. Did you notice the 4 easy payments of 14 cents?….,”

Yeah I saw that and cracked up. Hey I can finance my taillight bulbs! I’ve been ordering Hella bulbs from Summit Racing the last several years, including headlight bulbs, and have gotten great results with them. Probably better longevity than the usual GE or Sylvannia bulbs that the mainstream auto parts stores offer at ever-escalating prices.

Same goes for NGK copper core spark plugs. You can often find them online for under $2 each with a little shopping around. And Volvos love them.

I remember when I had a 240 one side of.the tail lights keep failing. I ran a ground wire from the "lighted" side ground to the failed light ground.

Thanks Dave and KGV, ooops sorry I shoulda added my little problem child's are both wagons, but good stuff just the same. I was able to find Sylvania LL 7528 and 7506 in the 2 bulb packs at Advance pretty easy and have since gone through both wagons, replacing all the bulbs, cleaning the contacts, bending the tabs out using dielectric grease, etc and actually changed out both tail light assemblies on one wagon due to the notorious heat damage to the brake/tail socket. Discovered that it's easy to hook up the wrong wire easy enough so that the brake filament is powered by the tail light and since I drive with my headlights on all the time, that would definitely be bad. Fortunately the lopsided brightness clued me into my mistake.
Before that work I did notice that hooking up an alligator clip jump wire to a reluctant turn signal on the positive lead reactivated it, so that may be a future quick fix, easy enough to do. BTW Advance does NOT sell C4.