Turn Signal Relay Buzzing?

[acbrock]

I fired the car up today planning a test drive and I am suddenly getting a buzzing from the Turn Signal Relay.  Is that the relay going bad or have I pinched a wire somewhere?

[acbrock]

Ok to add some insult to Injury.  Fixed a leak I had so I fired her up to let her run for a little while.  I did not do anything to the electrical but remove that Relay so it would stop buzzing.  When I start the Blue High Beam light is on.  Won't go off.  One the blinkers on the instrument panel is lit up.  I assume this is just because I pulled the relay but.... the new problem.  when I went to turn the car off... It would not turn off.  Unplugged the battery and tried again nothing.  Turn the key all the way to right like I was starting it, and it turned off.  Could pulling the relay out cause all these new issues?  Tomorrow if I am going to get under and take a look and see if I have any wires pinched or something.  Was really hoping for a drive today.  Hopefully tomorrow.

[acbrock]

Hey so when I get back into this tomorrow is there a quick safe way to turn the car off if the key won’t do it?

[BobH]

Hello, don't disconnect the battery with the engine running, probably best to remove fuse 4, to stop the fuel pump, and then wait until the engine dies, and then disconnect the battery

I can't see why unplugging the turn signal relay would cause any issues, perhaps you have a problem with the ignition switch, have you removed that, or carried out any other electrical repairs or replacements?

Just saw a post from you where you had the column switch removed and repaired, are you sure that all went back correctly?

[Cees Klumper]

You can also remove the signal wire to the coil - no spark = end of running.

It sounds like you may have some major electrical grounding issue somewhere, that can cause such inexplicable/unexpected gremlins.

[acbrock]

Ok thanks.  I think I got the column switch together.  It was when I put it all in a few weeks ago.  I did take the light control with all those wire and took each one off and cleaned them.  They were covered with that white melted plastic that the whole taking the dash apart a long time ago!  I will pull it all out and check all my photos and make sure I put it back in and don’t pinch anything.  Fingers crossed.

[acbrock]

So pulled everything apart and put it back together.  I took the wheel off too, thinking maybe there is an issue their.  The car had a Nardi on it, I bought a Benz wheel that I was going to use while restoring the wood on the Nardi.  Thinking maybe they have different connections.  But fired her up, starts and stops fine.  Ignition switch is good again.  Still getting the Blue High Beam Light on and Buzzing from the Blinker Relay.  is there a way to test the Relay to see if it is working or bad?  I will look around online...

[acbrock]

hmm.  maybe I am wrong.  I was reading all the tech manual stuff and my relay does not look like any of the relays in the pictures.  Is what I have posted here the Flasher Relay?

[BobH]

That looks like a turn signal relay from a much later car, has it ever worked?

Not being funny, but you do know the high beam light is controlled by the switch in the foot well

[acbrock]

Yea I was clicking the foot button but to be honest it is bright sunny and I am alone so I could not tell if the high beams when on and off.   Yes the Flasher/Blinkers did work until this buzzing showed up 2 days ago.  So looks like this relay only affects the blinking of the Flashers so I am going to see if I can get some other bulb to flash outside the car.

[acbrock]

ok so set it up with a light on my desk.  As soon as I got the last cable connected the light went on and it was Buzzing, but NOT flashing.  So I am guessing there is an issue with this Relay.

[acbrock]

Went down to the parts store.  I guess I know why in the Tech manual all the pictures are of the Barrel/Flat terminal variety!  The Bosch one from the car was findable but about $150 and would have to be shipped the Barrel one is $6!  I guess I will see tomorrow if I can get it all to work!

[acbrock]

Relooked at the tech manual.  I take that back out the Relay.  I guess Bosch just makes a ton of them.  I assume this one is not of the same quality so I am going to find a Bosch.

[BobH]

Originals can still be found if that's what you prefer

https://www.2040-parts.com/mercedes-bosch-turn-signal-relay-new-001-544-39-32-i1080125/

[acbrock]

Cool I think I will try and get it all working with one I just got.  But plan to track down an original at some point and replace it. 

[acbrock]

Excellent day!  Took her down to the beach with my son and then a drive with the wife!  Everything is running great but the new issues!  Today the gas gage is not registering.  Tach is good.  Speedo nothing!  Blinker issue that hopefully I fix tomorrow.  Speedo.. I cannot see the little pin it rests on, it is under it... could it just have gotten jammed on top of it?  I am going to get a magnet and see if I can move it.  Or take it on the freeway and see if enough speed will pop it off!

So I know electrical is a cray nightmare.  A few things.  I have a few things unplugged, like the Washer Motor and a few things like that.  Are any of these items daisy chained so unplugging one might affect another?  Like I realized today after pulling the car out that I did not have the right headlight attached or the right blinker!  But attached and still got the buzz from the relay.   I am sure this is just a me and the car slowly working thru things...

But great to drop the top and cruise to the beach today.  Daughter comes home tomorrow and I promised it would maybe not be "DONE" but drivable!  and I consider today a WIN!

PS thanks all the help along the way!  This forum has been amazing.  Now way I even try and tackle any of this without it.

[acbrock]

So I am working on the wiring.  Wired in a new Flasher Relay.  When I try them I hear the relay clicking but nothing.  When I turn on the headlights the right Blinker light stays on in the dash? The hunt continues.....

So I replaced a piece on my headlight and blew the fuse.  I replaced it and went to test the headlight and it works fine.  I then noticed the headlight go on with no key in the ignition.  Is that the way it should work or do I have a big electrical problem on my hands?

[Benz Dr.]

Head lights are wired directly to the battery so you don't need the ignition switched on. Actually, all power goes through the head light switch first before it goes to the ignition switch.

[acbrock]

ok cool that's good.  I guess I will search around the forum and see if anyone has posted a way to check all the electrical connections and I will start trying to find out where I F'd up.
s

[Cees Klumper]

I still think you have a bad ground somewhere, for example one of the lights/turn signals. Do you have a multimeter so you can check the grounds? With the multimeter on 'continuity' (beep) hold one probe to a known good ground, and the other probe to the light armature that should be grounded.

[Pawel66]

It is difficult to try to come up with ideas just on a description sometimes….

“When I turn on the headline, the right blinker light stays on”. Maybe I am missing something, but this is the moment I would take a look at the right headlight and right tail lamp…

You have the wiring diagram in the Technical Manual. With that and multimeter you can trace quite a lot, actually.

I do not know how fluent you are in these topics, perhaps it would be good to have a professional electrician look at it. I am getting a little worried that if you have a damage to harness anywhere (and that is why getting some of the strange symptoms), it may get dangerous at some stage. The car electrician does not have to be fluent in classic Mercedes if you show them the diagram.

That is what I would do if I could not figure out some obvious culprits.

[lpeterssen]

Dear acbrock

Check if your brake fluid reservoir switch keeps the circuit closed all the time.  That is a known issue that will cause the car to stay on since it produces a back feed to all T15 circuits if driver door is open at the same time.

Best regards
Lp
Www.wiredoktor.com

[acbrock]

Cool I will read around and play with my multimeter and see if I can find anything.  I will try and test all the lights today work my way into the harness.  I was watching some videos last night on how to text for ground.

I was looking at the other functions that should be on the Blinker Arm.  I tried the wipers and got nothing.  I tested the motor at it was fine so might be the arm is screwed up.   But I will test a few more things.  But at some point I will have to give up so I don't make it worse!  But not quite there yet!

When testing stuff.....I knew how to start the Wiper Motor at the motor because I took it out and apart to fix and clean up.  But I went to test the next spot which would be the Plug under the dash.  Seeing if I could get it to run with the Arm not plugged in to isolate it to the Arm.  Hoping would be straight forward but I was wrong.

Looked at the Plug and saw there were more pins than I expected. 2 Wiper Relay (Terminal 56) 4 Wiper Motor 7 Wiper Motor Relay (Terminal 86)

My thought (not knowing any of this)
I would supple 12v to  4/Wiper Motor and then 12v to a relay but there are 2?  Do I do both to get the motor to run?  Also I would attach to the Ground?  Or do I have this all wrong?

Then I was going to try and test continuity on the arm parts... and ground.


Also I wil check that Fluid Reservoir and see if that is causing the car not to turn off.  Because after not doing it a bunch of times it did it again yesterday.

[BobH]

Wiper motor and wiper relay connections and test procedure are on here

https://www.sl113.org/wiki/ChassisBody/Wipers

Luckily you won't have the low brake fluid switch or the door open warning lamp on your 230, so you don't need to worry about them

[Leester]

Having gone through similar issues a couple of months ago, I know how frustrating electrical issues can be. First, I would follow Cees advice and ensure that all grounds have positive contact with the body where the grounds are secured.

I also needed to learn and understand how the various functions are controlled. For example, the multi-function switch controls the turn signals, wipers, wiper fluid and if connected the flash to pass function. So any problems you have with those functions, such as your turn signal flasher buzzing, will involve the multi-function switch wiring.

I studied the wiring for the center instrument cluster to better understand its functioning. If your fuel gauge is not working or if your high beam light stays on, that is where I would focus my attention.

Like you, I had multiple issues going on and had to isolate each one and work on it separately. As you already know, the tech manual is your friend as is the search function.

Pawell's advice here is also worthy of repeating. The wiring in these cars is over 50 years old and who knows what previous owners have jury rigged to fix this or that. Electrical issues are not my forte but by focusing on one issue at at time, and with help from forum members, I was able to sort out all my issues but I will confess, it was tedious work.

The last lesson I learned that is obvious, but so easy to mess up, is that each electrical connector has male or female pins. These pins are arranged in mirror image. I can't tell you how many times I arranged the pins backwards after taking the conncectors apart. So, if you take the connectors apart, double check that you have the correct pins in correct sockets. I ended up making a diagram each time a took a connector apart and checking that the pins were in the right place - recognizing that the male and female connectors were arranged in mirror image.

I found success by focusing on one issue at a time, researching the tech manual and searching the website.

Stick with it and as you've already discovered, there is lots of help here.  Good luck.