Quantcast
AWD - 3rd brake light - very random

Volvo AWD 850 Forum

INDEX FOR 7/2019(CURRENT) INDEX FOR 5/2004 850 INDEX [<<]  [>>]

THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

3rd brake light - very random 850 1995

The little dash warning light lets me know something is wrong. For a long time I though the dash warning light was lying to me as I forget all about the 3rd brake light. I replaced the bulb a few times even with an Osram euro bulb. Cleaned up the contact a bit with my big fingers. Still very random. I'm starting to think it's got nothing to do with the bulb or bulb holder. I could try a LED replacement but I've read that screws up the bulb warning system due to LED's different behavior. Can't be the brake pedal switch. I really wouldn't care but the cops could give me a ticket and then I have to go to a gas station and pay $$ while i coax it to work.





Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

3rd brake light - very random 850 1995

issue solved?
tried using lamp-module from another person?





Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

Progress 3rd brake light - very random 850 1995

Well I think the problem is the connector that hits the center peg on the bulb is some cheap SPRING steel. I think it fatigues, the clue was the light seems to work initially but not after a few stops, so maybe a little heat from a few stops and the spring is gone. So I push that center tab against the bulb. At this point the black cover is always off so I have good access to the bulb. Concerning grounding - I think it is some kind of pass through circuit as I figured the outside connector for the bulb was ground but when i clip a ground wire on to that it just blows the 10AMP fuse.

The solution would probably be to get the new piece that holds the bulb, No idea if that's available from volvo. I tend to avoid used parts as I imagine i have one of the lower mileage 850s so used parts most likely are worse than what I have.





Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

3rd brake light - very random 850 1995

How is the third brake light grounded? I once spent nearly two days tracing a problem (with the fuel pump, but the lesson applies) that turned out to be a ground wire that was intermittently failing due to a loose screw and rust at the place where it attached to the body.

Contacts can make a difference; every time we take a trip in our RV, I check the lights, and often have to open up one taillight and look sternly at the contact points, which somehow causes them to work again. But, if you've cleaned and brightened the contact points, that shouldn't be an issue.

Got a multimeter? See if you can trace the current path for a failure point, starting from the hot side of the light fixture/contact points.





Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

3rd brake light - very random 850 1995

Would you please define your problem in better detail ?
Is the high brake light failing to come on?
Does it fail intermittently and the bulb is OK?










Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

3rd brake light - very random 850 1995

Would you please define your problem in better detail ?
Is the high brake light failing to come on?
Does it fail intermittently and the bulb is OK?










Cut and paste link:



  REPLY TO THIS MESSAGE    PRINT   SAVE 

3rd brake light - very random 850 1995

I have same problem. Replaced bulb, still random. I believe it in the wires at the third brake light. There are male and female clips on the wiring in the box cover. I clamped those tighter and seems to help. I want to trace the other ends under the shelf and clamp those down a little harder.





Cut and paste link:



  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

3rd brake light - very random 850 1995

LED brake lights will mess up the Bulb out sensor.

Step 1. Get new bulbs and replace all three with the same batch bulbs.

See if you get joy with that. (all three light OK and no idiot bulb out light)

Happy new year, Bill





Cut and paste link:


<< < > >>


Users marked in green are currently online.

©Jarrod Stenberg 1997-2016. All material except where indicated.


Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.

All participants agree to these terms.
Powered by Denizen - Custom Software for Enthusiasts