240 DL Sedan 1990 Tail Lights

jon53 · Post by **jon53** » 14 Jan 2010, 18:59

A few days ago I noticed the brake light in the rear window was on when I turned on the headlights/taillights. When I stepped on the brake pedal, the rear window brake light came on a bit brighter. I could also see reflected against the garage door that the left and right brake lights were also on with headlights/taillights and that they too became a bit brighter when I stepped on the brake pedal. A few days later, lighting returned to normal except the left taillights would not illuminate when I turned lights on. However, brake lights worked normally, as did reverse and turn signal. Light bulbs are all OK. With the light switch set to parking lights, I tried resetting the plug into the left rear light assembly and noticed that the brake lights again illuminated at one point, including rear window brake light. When fully reset, left taillights went out but brake, reverse, and turn lights all resumed normal operation. Any ideas?

Post by **billofdurham** » 15 Jan 2010, 12:07

Welcome to Matthew's Volvo Site.

I would suspect a fault in the plug or the wiring leading to it. Check both carefully to see if any insulation has broken down.

Bill.

jon53 · Post by **jon53** » 15 Jan 2010, 15:24

Thank you, Bill, I will look at it this weekend and report back.

pet19821 · Post by **pet19821** » 17 Jan 2010, 03:55

i just started having a simlar issue. i was looking at the wiring diagrams and noticed that the 3rd brake light runs off the drivers side brake light. if you have a bentley manual look in there. my issue is i put in new tailight bulbs and then there was some smoke and now the drivers side brake light works as a running light but will not illuminate as a brake light. the bulb out indicator comes on when i push the brake pedal so the smoke was probably that circut shorting out. but also a thing to consider is the bulb failure sensor in your case. if the wiring has gone funny there it can reak all sorts of havoc.

Post by **billofdurham** » 17 Jan 2010, 12:06

i was looking at the wiring diagrams and noticed that the 3rd brake light runs off the drivers side brake light.

The Volvo wiring diagram has the 3rd brake light running from the bulb failure sensor direct. Running it from the driver's side brake light would put the system out of balance and the bulb out light would come on.

Bill.

pet19821 · Post by **pet19821** » 17 Jan 2010, 14:33

oh yeah i was looking at the ground path doh

jon53 · Post by **jon53** » 17 Jan 2010, 15:11

I took in all apart, cleaned contacts, and reassembled. I think the problem is in the plug attachment--wires to circuit board. Everything worked as advertised, put the cover back on, closed everything up, and the tail lights didn't work (brake lights did). Opened it back up and reset the plug, it all worked again... closed it back up, still worked... but I'm not optimistic it'll stay that way.

BTW, I'm having similar problems with the right taillight.

Post by **billofdurham** » 17 Jan 2010, 15:29

It looks like you are going to need at least one connector, which is listed as "Insulator uncoloured 8 pole", part number 949543. It is doubtful if a dealer will have them in stock and a quick check of our sponsors hasn't shown them. Erie V0-Vo my be able to help.

Bill.

LikeAGloveBox · Post by **LikeAGloveBox** » 23 Jan 2010, 19:55

If you find this connector, please let me know where you found it. I'm having similar problems with my 1990 240. I started out thinking I was just going to replace one driver's side tail light. A friend took some wires and ran them from the same bulb connector on the passenger side to the driver's side which actually made everything work for a couple weeks. Wasn't my idea. I don't know if that made things worse for me or didn't really do anything at all. The bulb connector in question at the time wasn't contacting the circuit board so maybe we unwittingly fixed that while we were jostling the wires around. So a couple weeks goes by and everything was working fine when my "brake failure" light comes on and I have no running lights or brake lights. I just went ahead and replaced both of the tail light assemblies, complete with new bulb connectors, new bulbs, and new circuit boards. I now have running and brake lights on the passenger side and nothing on the driver's side. I looked at the 8 pole connectors though and a couple contacts on both sides look discolored/burned. I applied a continuity tester and it doesn't light up on those particular contacts. I had some de-oxidizer on hand. No luck with that of course, but it was worth a try, right?

I forgot to mention before and after our cheap wire rigging job, but not right after when everything was back to functioning, the front driver's side marker light was/is out.

Anyway, yeah, let me know if you find this part please.

Post by **billofdurham** » 24 Jan 2010, 11:50

LikeAGloveBox, welcome to Matthew's Volvo Site.

This problem is becoming more common as the vehicles age. I have been trying to work out a solution, probably using non-Volvo parts but so far haven't found anything compatible.

You mention "brake failure" light. Was this not the bulb malfunction light as the brake failure light should only come on when the brakes fail?

If it was the bulb malfunction light it should have come on as soon as your friend jury rigged the lights. The lights are wired individually and the bulb malfunction sensor detects when one side isn't drawing current, ie a bulb is out, and lights up the malfunction light. By wiring from the other side you had only one circuit active. Is that light still lit?

The failure of your new lights could be a result of a faulty bulb malfunction sensor.

Have you checked/changed the bulb in the driver's side marker light?

Bill.