Rear blinkers don't work

[bmw2800cs]

Hey all,

I've been trying to get my turn signals to work, after changing a fuse and the hazard switch I've got the front turn signal/hazards working but the dash light (in the speedometer) and the rear signals don't work. Any ideas why? Neither the left nor right rear signal works.

 

[Norm!]

My left one stopped working recently after I had the spare tire cover off. It also caused the dash indicator to not work after one blink. I assume you've already checked for blown bulbs, but it is unlikely to be the cause since both are out. Next check for loose connections starting in the trunk. I got lucky and fixed mine temporarily by wiggling the connection on the outside of the bulb housing. I haven't yet taken time to find the fault but it should be easy since I am nearly at the bulb connection. Others will have more ideas than me about other specific things to look for because, like you, I am just a beginner when it comes to E9s. Good luck.

 

[Arde]

It must be the wiring to the rear assemblies, or the connection, or the ground, or the bulbs.
Fuses are fine if front works. Did rears and dash light work before? I cannot see any individual problem that would affect all three given that fuses and solid state blinker work.

 

[Thomas76]

If brake light works it suggests ground is ok?
What about the wiring/circuit on your new hazard switch? Connections ok? Correct switch.

 

[Sean Haas]

could be a number of reasons but in my case it was a wonky connection where the wire plugged into the light assembly which was easily fixed - certainly easy enough to check along with bulbs

 

[Honolulu]

Well well well, I haven't seen this problem crop up in a long time. From my own experience, the flat copper "bus bar" across the tail lights is riveted on the bulb sockets with steel rivets, and of course galvanic action builds up corrosion between the bus bar and sockets... lights no workie.

How you address this is up to you. You could go full OCD: drill out and install new (copper) rivets if you can find them, but it's simpler to run and additional ground wire connecting each socket to a ground point on the body or the brown wire leading to the correct ground.

This is a case where simply verifying power gets to the sockets won't solve the problem, which lies on the ground side of the bulb.

 

[bmw2800cs]

Well well well, I haven't seen this problem crop up in a long time. From my own experience, the flat copper "bus bar" across the tail lights is riveted on the bulb sockets with steel rivets, and of course galvanic action builds up corrosion between the bus bar and sockets... lights no workie.

How you address this is up to you. You could go full OCD: drill out and install new (copper) rivets if you can find them, but it's simpler to run and additional ground wire connecting each socket to a ground point on the body or the brown wire leading to the correct ground.

This is a case where simply verifying power gets to the sockets won't solve the problem, which lies on the ground side of the bulb.

Thanks! I'll have a look.