Hello everyone!

I was told this morning that my brake lights had stopped working. I have power out of fuse #7, and all bulbs are good, with clean contacts on the bulbs and holders. The Brake Failure light is not on.

I've read Art's page about the switches being very reliable. Any ideas? Perhaps the relay?

Thanks!
Jim

My bet is on the bulb out sensor relay. The brake light circuit is often the first one to go in my experience. The bulb out indicator warning light may or may not be lit, in your case it won't be as both sides are affected.

It's often best to diagnose this starting at the bulb sensor relay. Pin 54S is voltage in from the switch. The corresponding point in the socket is a convenient test point to confirm voltage is present when the pedal is depresssed.

Failing that, wrap a jumper around the base of pins 54S, 54R, 54L and S (S is the 3rd brake light). Be careful not to short to neighboring pins, safest to bare only where you do the wrap, which is a bit more tedious. Thin 16G works fine for this, preferably solid core so there are no strand tails accidentally sticking out and less likely to be broken during insulation stripping. Re-install the relay and if the brake lights now work then you'll know that's it. You can continue to drive this way until you're ready to replace the relay or attempt to repair it.

Re-soldering the relay fixes it 90% of the time, one of Art Benstein's favorite repairs. If you want more information there's lots to be found on this site and others. Pay particular attention to re-flowing the solder on all connections for those same pins, esp. pin 54S in our case, following the traces on the lower board to the upper board as needed. Be carefully about moving the sensors that run through the middle of the coils, the ceramic glass coating is brittle.

Second after that will be the brake light switch at the pedal, which you can confirm as above or by measuring at it's connector. These cars are at that age when those switches are starting to wear out. As mentioned by others, diagnosis can be done at the switch connector with a meter, test lamp or even using a jumper wire. If you happened to have cruise control, there would be separate switches at the pedal. The cruise control switch has a vacuum tube on it.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Hello Everyone,

Sorry about the delay, thanks for the great responses and info.

My red canister bulb out sensor doesn't have pin 54S, only pins 54R, 54L, and 54. Either way, there's no power going to any pins when the brake is applied. Does this mean the brake switch is bad?

Thanks so much everyone!

One of the earliest posters suggested you use a simple 12 volt test light at the brake switch in and out to be sure.

Just do it

Hey Bill,

Thanks, agreed, I couldn't easily get to the switch. I pulled the speedo this morning and saw that the output from the switch looks a little funky. I cleaned it and have power out. I still didn't have brake lights though. I pulled the red canister and the main power into the second pc board had corrosion around the pin, resoldered and now I have brake lights! Now to clean and reassemble everything!

Thanks so much for everyone's expert Volvo information!

Much thanks to planetman, BB, machine man, Art Benstein, Amazonphil, Dave Stevens

You guys are the ultimate Volvo 240 experts!

Hi,

Glad to hear you ran that problem down. Appears to have been quite a chase inside the bulb out sensor.
I wasn’t aware of two circuit board levels inside it but then since it had corrosion you might want to see where some moisture is coming from.
I blame lots of this on wet shoes but a windshield corner is another possibility.
Did look like it got water in it?

Thanks for including me in the list with those others more knowledgeable than I.

These forums sure do help to cut down on the expense of paying for a repairs.

Our contributions to a forum help avert the cost of living and the cost of using the Internet.

Phil

Hi Phil,

Thanks for the response. The corrosion was very light, just fuzzy grey lead dust around a loose joint where the tab from the first board connects into the second. Everything else was dry and looked like new after 32 years.

This wagon has been very good to me in the 22 years I've owned it. It was basically new when I bought it, low miles and many things had been replaced already. It was owned by the local Volvo dealer's wife, and the dealership kept it immaculate. I'm pushing toward 500k miles now and it's about time for some suspension maintenance. The only thing I've done is one set of tie rod ends a few years ago. My next project is new rubber bushings all the way around. Maybe poly on some of them.

Thanks to this great group who've helped me through another little blip.

From my wiring diagram, the 12vdc power goes through the brake light switch first, so I assume I need check here first, since I have no power to the bulb out sensor.

Will I need to remove my speedometer cluster to access it?
Will I need to remove the steering wheel?
Thanks

"I have power out of fuse #7..."

If you're measuring that power with a multimeter while the brake pedal is not being depressed, you may be fooled by the sense voltage that appears there from the cruise control. This is voltage with very small current capability, not nearly enough to light a bulb. Best to check this power and trace the circuit with an incandescent test lamp instead of a multimeter. Also, without the load, a cracked fuse element or corroded end can make a meter show power up until you complete the circuit with the brake pedal switch.

If you're sure about the fuse and its contacts, the next usual problem is the bulb failure warning sensor -- broken solder inside. Use your test lamp to see if pushing the pedal switch gets power to the pin 54S (blu/red wire) and out again on the three brake lamp wires, pin 54L (yel/gray), pin 54R (yellow), and pin S (brown/black).
--
Art Benstein near Baltimore

good tip to use a bulb instead of a meter so it isn't fooled by voltages with no amperage which can show up and confuse someone with a DMM.


maybe this seems like a radical change ,,

all you really would need it to use a brake fluid pressure sensor from an older car and then just pick up power from an unused fuse or add one,

run that to the brake lights and then to ground. simple! 1 wire running two bulbs.

That would eliminate a whole lot of unnecessary complication.

Volvo prided themselves on making good safe cars but I think they got led astray with this section of the wiring. It's way more complex than needed and that over complexity in itself caused a system that was prone to failures and caused owners much grief in trying to wrap their heads around it all.

Hi,

I would definitely check the brake light switch first.
Since you have to go under the the dash and behind the knee bolster to get to the switch you will find the bulb out sensor near there.

The switch itself is a plunger type. It activates by being moved outwards or being released of pressure on it. It can get sticky or corroded on its terminals as there can be moisture of wet shoes from time to time.
Try the terminals first to clean them.
While they are off attach a volt/ohmmeter to the spades and activate the pedal for a continuity check.
You want the switch to be on shortly after the pedal being depress and before the brakes pump up but go off every time so the cruise control will operate.
If it the switch it will not work so I ask do you have a cruise control?

They can stop working by either electrical or a vacuum valve on clutch versions.

I’m not aware of brake lights being grounded through a transmission circuit or a relay being used. So that a new one to me. But it’s plausible and worse with the newer cars and their sophisticated electronic monitoring.
Be happy that this is a somewhat simplistic 245.

The brake bulbs or rear lamps housings should have their own ground returns.
That would be the next possibility in the tailgate third light and could be a hinge problem with the grounds back there.
Since it’s all three you will have say the pedal switch should first and then keep looking if not.
The bulb out sensor only works when there is a current draw difference from the right to left sides of the car.
If there’s no lights at all, the sensor doesn’t see a thing! Consequently no indications.

Hope this helps to open your view to the wiring system, as squinting at those wiring diagrams, takes due diligence.

Phil

"I’m not aware of brake lights being grounded through a transmission circuit or a relay being used. So that a new one to me."

Me too, Phil.
--
Art Benstein near Baltimore

Check the brake switch function,
and for possible open (needing solder reflow) Bulb out sensor pin/s 9,10,11.

What/where is the bulb out sensor? Thanks

Hi Jim,

I'm using the 1993 Volvo 240 wiring book TP32252-1
It points to the left side of the dash in back and left of the instrument cluster
for the bulb out sensor.
Make sure the brake switch is actuating, if you can get at the bulb out sensor socket find +12VDC at pin 9 when you actuate the brake switch.

You really want to find the Volvo wiring book for your car, without it, you're
up the well known creek without a paddle.

Good luck, Bill

Hi Bill,

I have the manual. I'm curious why the Brake Failure light is not on even though I have no brake lights working. Ideas?

"I'm curious why the Brake Failure light is not on even though I have no brake lights working."

The Brake Failure light is turned on when the brake fluid is sensed low in the reservoir. It hasn't anything to do with the brake lights.
--
Art Benstein near Baltimore

older cars sensed the brake fluid pressurre but then they went ot the switch on the brake pedal.

I love that for tailgaters as I can step om my brakes enough to make the brake lights come on while a the same time accelerating away from their front bumper ;-)

Beginning 1991, the brake failure light works from a fluid level sensor in the reservoir. 240s through 1990 used a differential pressure sensor to turn that light on when a loss of pressure occurred in one of the two brake fluid circuits.
--
Art Benstein near Baltimore

there might be a different idiot light for that low reservoir

Im not sure about 92 but every 240 I oned had that stupid bulb check system , look for a big round red thing near the steering column.

I think the system compares the amp draw from left to right and if its different , like if you have a bit of corrosion or different bulbs it comes on and drives good men crazy.

If you clip the ( red? ) wire to the idiot light I would understand, but it's not "correct"

if you have deep pockets you cna sometimes replace the circuit boards that are the tail light wiring, they always seem to get scratched and loose contact, the newer they are the worse and thinner they got from all I've seen with them. I went to the extent to rip all that out and install all new regular style reliable light bulb sockets to get rid of those issues.


If you want there is a space for a brake light or a signal that is not used in North America at least in the sedans. Its a blank spot with a red lens. In europe it would function as a parking light , not needed over here. If you like you can stick an LED bulb in there in parallel with a brake light for extra insurance. a car that new will also have a third brake light.


it could be relay related.

Id unhook the battery, pull a few fuses and then find the two Phillips head screws that hold that whole fuse bar in , it will pull out a foot from the car ( remove that one trim panel) and then you can clean all that really well and also clean all the spade connectors. get a can of deoxit and something to scrub any green away , I have a thing that is like fiberglass strands in a pen that I like for that, or steel wool works fine , just clean up the remnants. chuck or clean any green fuses. if it doesn't fix your brakes it' ll fix something else because they are problematic

steel wool does burn so be wary of that, one would think steel was non flammable but if you make an arc you can get a good fire going by accident using a bit of steel wool.

the pedal switch can be the issue, especially if you have no lights at all. often the issue is that the tail lights work ok but the idiot light comes on to tell you you have a bulb issue. earlier cars sensed the brake fluid pressure but that car should have a switch right on the brake pedal , I htink I remember a spring hooked to it.

I check mine when I'm in front of a store with big windows , just look for your own reflection and test like that. no helper needed.

I think there is also a check engine light that gets triggered by the speedometer. If you pull the speedo out look at the back for a lever thing, I think its supposed to signal you to change your timing belt and then it comes on for about 5 mins upon each startup. I think that thing runs off the speedo and often the numbers stick in those speedos then the speedo works just no odometer or maybe no trip counter.

look if it has a trailer. if you wanto pull a regular 4 pin trailer with a volvo then you need an adapter to make trailer lights work , sometimes if there is or was a trailer the former owner may have hooked in to the wiring harness to do that. typically twisting the wires and no solder or those squeeze up crimps or some other faulty connections.. and problems to follow a year or two after that poor wiring job.



a volvo does not use the same bulbs for signals and brakes, but a ford or some US car does. by sharing the signal and brake they save a wire, you can add a unit to transfer from one system to the other if you like . then if you go rent a trailer the plug will be a typical run of the mill 4 pin trailer plug.

check against a manual for the bulb types, It's best to make sure the bulbs dont just fit but that they are also the right bulb number and wattage and also if you change bulbs always do two so they draw the same current , otherwise the bulb failure indicator goes troublesome.

volvo really over complicated the brake light system and that led to a lot of unnecessary failures and confused owners.

The third idea could be a dead idiot light for the bulb out sensor.

Hi,

That’s right too.
He didn’t say whether it came on with the other lights before starting the car.

If the bulb out sensor loses the circuit inside its self does it or can it kill the lamps?
That doesn’t seem to be a good safety feature if it’s operates that way.

Phil

It would be helpful to know which transmission you have. If it's standard shift the wire and switch at the transmission that provides ground for the relay is a possible trouble spot. = Dave

I have an automatic. Thanks

Sorry about yelling, but DID YOU CHECK THE POWER GOING INTO AND OUT OF THE BRAKE LIGHT SWITCH AT THE BRAKE PEDAL!!! All you need is a simple test light.

If the brake light switch is faulty, the bulb failure relay will not indicate a failure. The failure relay only lights up when there is problem with the bulb(s) or the wiring between the relay and the bulbs.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com