I just bought a '92 240 sedan and am having trouble with the brake lights and the tail lights. I remember my 244 had a tail light that came on every time I'd go over a bump, then switch off again on the next bump.

I had a mechanic do a buyer check for me and he let me know that the middle brake light in the window was the only one coming on. Called up a local Volvo mechanic and he said it was probably the bulb failure relay and recommended I replace it. I went ahead and replaced that today but everything is still acting up. On some of the bulbs I can't seem to get a stable connection - if I turn it all the way, it switches off. If I turn it about halfway it stays on until I do something like shut the car door - which not only turns off that light but a couple others as well. I have the annoying thin circuit cards in the tail lights which I have heard can cause some of these issues. The most bizarre thing though - I turned the car back on at one point and the middle window brake light managed to turn itself off! That makes me think it's just not a circuit card issue.

I suppose if I really tried I could get the bulb failure relay on there just a tiny bit tighter, but I feel like it's about as tight as it's gonna get.

I don't know a whole lot about cars in general but I like understanding how things work and am hoping to get a better fundamental understanding of the parts that make up the whole lighting system and what each part is responsible for.

Just wondering what my list of potential issues could be and if it's something I can fix myself or something I need to have someone else do for me. I like doing stuff on my own when I can, but I don't have a whole lot of tools.

I saw one suggestion in quite a few places was to hardwire everything so you don't have to deal with circuit card issues. A couple people said you can use an old GM bulb holders are already hardwired and can fit in the slots on 240's. Wondering if that would be a good option for me:
Hard-wiring 240T tail lights [Archive] - Turbobricks Forums

 

its likely either the wiring, or the sockets themselves. I'd check the voltages at the various connections with a meter. you'll want the wiring diagrams for a 1992 240

if your signal lamps are clouded and cracking and/or corroded, I'd suggest replacing the whole things, all the way around. fresh headlights and tail lights makes an old car look 10 years newer

 

i dont drive 244's, but i hear the tail light circuit board goes bad.

 

On my 240s the point of failure always seems to be where the edge connector clamps onto the flexible circuit board on the tail light. The connector over time seems to rub holes in the flexible circuit board.

 

One of my taillights had a crack, which let moisture in, and over time fried the flexible circuit board. Replaced the whole one side, and on the other, I lightly sanded down (I used a 600grit metal sandpaper) the contacts for the bulb sockets, and cleaned/sanded the plug on the circuit board. Et voila! Working brake lights again.

I agree with Pierce though, replacing 'em all can't hurt!

Also, I had an issue where ALL brake lights intermittently worked (no bulb failure dash light illuminated), and that ended up being my brake light switch. The switch is like $10, takes 20 min to install. Can't hurt to replace that while you're servicing the system.

 

yeah, on the 240 sedans, a fundamental problem is that rain water from the roof runs down the rain gutters, and into the channel around the trunk lid, and down directly onto the top of the tail lights. when your tail lights get old and develop fine cracks, this water then gets into them. in heavy rain, the individual light boxes fill up with water which then sloshes into your trunk, as well as corroding the lights themselves. I've been known to drill small drain holes in the lower corners of each light cell to promote drainage and get another year or two out of a light, but I think I've replaced both of our 240's tail lights at least 4-5 times since we bought it new in 1987.

 

Alright, so I finally had some time to actually get in there and check everything out. After some fiddling with the block what connects all the wires to the circuit card to make sure it was on there nice and tight, swapping out bulbs and sockets, and swapping out new fuses for the tail lights and brake lights - I've got everything working except that the bottom right tail light won't turn on. The odd thing is it will turn on for the brakes, just not as a tail light. I noticed on the circuit card it's slightly melted/ripped on that one.

Could that be the issue, or is it unlikely since the brake is working? I have another circuit card from an old light that was left in the trunk (also where I got all the random bulbs and sockets from). The outside had been smashed a bit, so the whole thing was replaced. The circuit card is in there and looks like it's a bit higher quality than the one that's currently in there. It's for the correct side, but it's ripped in the exact same spot (though it doesn't look melted at all). Is it worth swapping it out? If so I just need to go pick up a T25 or T20 for that grounding wire screw...

 

Gosh dang it. I went ahead and picked up a T25 for the grounding wire screw and swapped out the circuit card. Then neither of the right side tail lights worked. Swapped the circuit card back to the old one - the right side tail lights are still out. Before it was just the right side one.

All the brake lights/backing up lights are still good luckily, but I was hoping to pass inspection with 3/4 tail lights. Probably not going to happen now with only the left side ones working.

The tail lights look pretty new - no cracking or anything, so I'd rather not swap out the whole things if I don't have to. Just bought the car last week and don't have a whole lot left to spend on it before.

Could I have blown the fuse for the tail lights if the left ones are still working?

 

Learn how to use a test light or a multimeter to check for voltage. Prob not the problem here, but it wont hurt to know how to do it.

Look at your fuses and list of circuits and answer your own question. Tails have a fuse for each side. Brakes use same fuse.

 

Okay, will look into how to test voltage.

I took a look at the fuses last night and they were still intact. Is it possible for a fuse to look fine but not be working anymore? In mine there's one fuse for the brake lights and one for the tail lights rather than left and right brake/tail fuses.

 

a failed ceramic fuses will generally fall apart if you remove it.

I highly recommend getting a kit of all brass/copper euro fuses, and replacing all your fuses on a old 240... clean any corrosion off the spring finger contacts with a fresh soft pink pencil eraser.

 

Yeah when I pulled out the tail and brake light ones earlier yesterday (very gently) they broke. I replaced those and maybe 3 or 4 others. I picked up a few more at autozone last night and will swap out all the remaining ones and try to clean up all the contacts.

The fuses I'm using look like this, is this the right kind? http://www.jbugs.com/store/graphics/...es_8_16_25.jpg

 

ahh, if they are copper/brass like that great. I've only ever seen the tin plated ones at US auto parts stores, so I've been getting them from vendors like Volvo 30 Piece Fuse Kit for 240 & 260 AFTERMARKET 105869 3E1000

for extra protection, put a tiny dab of dielectric grease on each end of each fuse, or a dab of DeOxIT D100, this will keep them from corroding for a long long time.

 

I was too lazy to go look, but yeah, start with fuses and work back from there. Find out where the 12v goes missing.

 

see, I'd start at the connector to the lights, ensure there's power on the appropriate wires going into the tail light cluster. if yes, then the problem is in the tail light itself. if no, its in the wiring, THEN go up to the fuses and split the problem space in half.

 

Okay, so I had a friend come over who knows a little more than me about car electrical stuff, but he’s more used to working on simple motorcycle stuff & he brought his multimeter.

Just like you guys said, he first checked if there was continuity between the plug going into the circuit card for the brown/white (tail lights) wire and the ground wire for the circuit card—there wasn’t. To make sure he was checking correctly, he also checked for continuity between the yellow wire (which goes to lights that are working) and the ground wire for the circuit card. That one did have continuity.

Can you guys confirm if that means what he thinks it means, that voltage isn’t getting to the brown/white wire for the plug that feeds into the circuit card?

Then he checked voltage from the battery’s positive terminal to the 5th fuse (which should be the one that feeds into the tail lights, as marked on the cover for the fuse section), and there was. Then he checked continuity from the battery to the brown/white wire that is attached to the harness for the bulb failure relay and that was working as well.

Also, not sure when/why this happened, but my left brake light seems to be permanently engaged now.

Did we miss anything? Any ideas what this means?
He left the multimeter with me for now in case I need to check anything else.

 

Continuity tests are interesting, but they are indirect. its better to measure the voltage relative to chassis ground at various points.

I would put that multimeter in dc volts mode, and clip the black lead to a solid ground (there's a ground screw not far from the left tail light... clean it before clipping to it), then I would probe both sides of each bulb socket when you think it should be turned on, and each wire at the connector. at the bulb socket, if any GROUND sides of any bulbs is reading voltage, that means its not actually connected to a good ground. if the hot side doesn't have power, then I'd probe the corresponding wire at the connector, and see if it has power, if it doesn't, then go investigate up front, if it does, then the problem is in the tail light fixture.

if there's no power on the correct wire for a given bulb circuit when that bulb is supposed to be on, THEN up front, its time to dig out the bulb sensor module, and test the voltage at the corresponding pins on it.

the wires to the tail lights run along the base of the left side of the car... if you remove the drivers side door sills, the wires are right there under the edge of the carpet, they go up near the back of the fuse panel and into the harness. most of hte bulbs come out of the bulb failure module, if you can get the pinout of that, check the voltages the same way (black voltmeter probe clipped to a good ground, like the main console ground on the transmission hump side just forward of the shifter, under the carpet), and probe live circuits with the red probe in DC Volts.

I'm going to be offline for 2 weeks, btw, so this is probably my last visit to this forum for awhile.

 

Okay, I'll check all of that. Thank you!