300 SD Electric Problem - PeachParts Mercedes-Benz Forum

nyko46 · #1 04-06-2015, 09:47 PM

After many tries and frustrations, on 04/04/15 I just finished the repair of my cluster panel which was not working after changing lights. Not working because the big round connector had the D mark broken and it was causing me to connect it in wrong position. With a help of people from this forum I finally got the cluster working again.
Now a new problem arrived: Emergency light does not work and is also causing other problems when I turn it on.
Here is what happens: with the ignition key on with the car running or not if I turn the emergency light on it will not work and it will turn the radio off instantly. It will also make the central lock system to work disorganized.
I mean; it will try to lock when it is already locked and vice versa
Radio will not come on again even if the emergency lights switch is already off.
The only way that I found to get the radio and central lock system working again is disconnecting and reconnecting several times the negative cable of the battery. It take a lot of tries doing this procedure to finally get the radio and central locking system working.
Just to give a try, this morning I was driving to work with the radio on and as soon as I turned the emergency light on my radio turned off instantly.
All fuses are good and all other accessories of the car work fine.
What can be the cause for this problem?

JamesDean · #2 04-07-2015, 09:22 AM

When you say "emergency light" do you mean the red hazard button on the center console?

nyko46 · #3 04-07-2015, 08:21 PM

That is correct.
It is a kind of problem tat I never had before.
This is the same car that "gave me" the problem with cluster panel.
Minutes ago I finished to work on the passenger front side electric window.
Still need to find out this issue with the hazard light.
Thanks

JamesDean · #4 04-08-2015, 08:37 AM

Just a guess but I wonder if the misalignment of your big round connector had somehow damaged the flasher relay.

You might need to replace the hazard/flasher relay. Part number 000 821 10 63. It about $20.

pmckechnie · #5 04-08-2015, 09:42 AM

When working on electrical problems it is very important to know the year the car was made. At least, is it a generation 1 or 2.

JamesDean · #6 04-08-2015, 09:56 AM

In his case, gen 1 w126. 300SD. Not sure of year though.

nyko46 · #7 04-08-2015, 08:54 PM

Quote:

Originally Posted by JamesDean

In his case, gen 1 w126. 300SD. Not sure of year though.

Mercedes Benz 300SD 1984

nyko46 · #8 04-08-2015, 09:00 PM

Quote:

Originally Posted by JamesDean

Just a guess but I wonder if the misalignment of your big round connector had somehow damaged the flasher relay.

You might need to replace the hazard/flasher relay. Part number 000 821 10 63. It about $20.

Is this the same relay for turn signals?
If so, my car turn signals are working great.

jbach36 · #9 04-08-2015, 09:26 PM

I don't know anything about your problem, but I just wanted to toss an idea out....

I was told a long time ago that even if my fuses were good, change them to the newer COPPER ones. The OLD metal ones might LOOK ok, but they might not BE okay. The old ones get pitted and it can cause a variety of electrical problems.

Good luck.

pmckechnie · #10 04-09-2015, 07:02 AM

nyko46,
Change fuse 13. These fuses can look good but when you take it out it will fall apart. Or it could just be a bad connection at the fuse and turning it may make it work again. I would still change it if turning it makes it work again.
By the way, fuse 13 is also used for the radio, clock, and a few other things.
It is the same relay for the turn signals and the emergency signals.
PaulM

nyko46 · #11 04-09-2015, 08:03 PM

Quote:

Originally Posted by jbach36

I don't know anything about your problem, but I just wanted to toss an idea out....

I was told a long time ago that even if my fuses were good, change them to the newer COPPER ones. The OLD metal ones might LOOK ok, but they might not BE okay. The old ones get pitted and it can cause a variety of electrical problems.

Good luck.

I agree with you in this detail.
In the past I had problems with fuses not making good contact due the oxidation at the fuse base.

nyko46 · #12 04-09-2015, 08:04 PM

Quote:

Originally Posted by pmckechnie

nyko46,
Change fuse 13. These fuses can look good but when you take it out it will fall apart. Or it could just be a bad connection at the fuse and turning it may make it work again. I would still change it if turning it makes it work again.
By the way, fuse 13 is also used for the radio, clock, and a few other things.
It is the same relay for the turn signals and the emergency signals.
PaulM

I will try that and see what happens.
I hope it works.
Thanks