fog light/turn signal/high beam flash issue
 

My '84 wagon has a issue(s). The fog lights work but heat up the fuse (#11) to the point where it blows in about 4 minutes. They work fine and I just replaced them and the wiring looks like it should at the lights themselves. Inside the car the multi stalk no longer allows the pull back "flash to pass" of the high beams. Pushing forward still engages the brights as designed. The blinkers no longer blink when it's pushed down- they stay lit so I have to manually blink so to speak if I want to signal a turn.

Anyone had similar issues? Help! thanks

It sounds like something may have come loose inside the combination switch.

I've never had that issue.
You could start by checking the resistance on each part of the circuit that goes through the switch.
Or
Just replace the switch.

Are you two referring to the the headlights switch or the multi function stalk? thx

I would think the stalk.

I pulled the stalk out and it appears fine with no wiring defects. The switch looks fine but I left it in place. The fuse box from inside looks fine from what I could see. Stock turn signals/corners.

Test the resistance on each section of the circuit that you can isolate. I would start at the light socket and work upstream from there.

Flash to pass works now after removal and external cleaning. Still no turn signals. Haven't checked the fog light fuse for warming yet. Hmmmm.....

Maybe change all your fuses to copper ones?
 

Someone told me early on to change all the old aluminum (or whatever that is) fuses to copper. The old fuses become pitted and increase resistance on other fuses and components.

I don't know anything about electrical, but I changed them. You can probably get a whole set for $15.

Mine's a 1991 300d.

interesting- I'll check and report back. thx


Edit: I'm also going to check the hazards switch to see if it operates and clean it if it does not.

I pulled the hazard switch which was a bit sticky and did not flash on and off. It broke apart and so I installed a spare I had which turns on but does not flash on/off. Is there a relay which is in the electrical path of both the hazard and blinkers that could be faulty?


Yes there is ....http://www.pelicanparts.com/catalog/SuperCat/3391/MBZ_3391_ELSWCH_pg3.htm#item11
Where is it located? anyone know?

BTW- I changed out the fuse to copper and with that plus the hazard switch cleaning the fuse heated up much faster... don't know that the hazard change out had anything to do with it however.

The turn signal flasher unit is under the wood shifter shroud.

Remove the Ash Tray and the metal bracket. two Phillip screws and lift it out.
Slide the Shroud back and the flasher is under it.

Silly question, but have you cleaned the ground points? There's roughly 6 or 8 ground points for the entire car. One of the first things I do when I work on a car is find all the grounds, clean them, add some dielectric grease, and make sure everything's tight. Bad grounds can make for some odd behavior.

So I pulled the shifter surround and boost/egt gauge which is in place of the ashtray. There is a relay but not like the one in the link I posted. I pulled it, looked at it and tried to take it apart. Did not succeed. Re installed it and now the turn signals don't turn on at all. So replacing that is next. I'll modify this post and insert a pic with my phone here shortly of the relay. Mobile pic uploads is disabled, ugh.

Hi MTUpower. I'm a new w123 owner. Thanks for your post. Did you ever work it out? I have the same issue. Low beams work fine. But if I turn on yellow fog lamps they light for a short while and then blow the #11 fuse, which takes out the right headlight low beam and both fogs. It is a red 16A fuse, copper. I'm new to these cars but the only thing I can think is it has two basic sylvania halogen headlights, maybe these draw more current than the OEM style so the fuse just blows? That doesn't see to make sense but hey I,m desperate.

Thanks. Patrick