Electrical Mystery

RogerB

RogerB

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I took my CSL out today to stretch its legs. I noticed that my turn signals do not work. I checked the fuse and it indicates good. The fuse legend shows the wipers and washers, stoplight, turn signals, horn, and backup lights are all on fuse #6. Out of these, only the horn and backup lights work. The turn signals were working the last time I had the car out in September for sure, but I didn't check the stoplights and wipers.

The turn signal lever operated the left and right Euro curb parking lights fine and the hazard flashers work fine, so I don't believe it is the turn signal switch or the flasher?!!?! I did discover something new after all these years of coupe ownership though: the under hood light comes on when the left Euro curb parking lights are turned on.

I would appreciate any thoughts as to what I am overlooking here.
 
I'm thinking bad hazard switch as part of the problem now. It won't turn off!! I had to pull the fuse to turn it off. Also, the Euro curb lights now work on the back and not on the front right at all; however, the front outside headlight comes on on the left side!! The wipers cycle twice when the washer lever is actuated. but don't move at all with the wiper switch. This keeps getting more baffling!!
 
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I had more or less that happen to one of my cars about 3-4 years ago.
I read somewhere about the Hazard switch. Changed it and it solved all problems.
There are 2 varieties. They look the same but are different at the rear end with regards to the contacts.
Both are available new.
 
WOW- talk about coincidences! I took my CSL out today and noted fuse six was blown! Replaced it and it blew as well. Replaced again and noticed my backup lights were constantly on. I played around with the wires to the backup light switch as the tranny was just replaced. No change. I swapped the leads on the backup light switch- same. My guess is simply a bad B/U switch, but is there a way to test? Does the switch connect/close a positive or a ground when reverse is engaged? Anyway, thought this post was pretty funny in terms of timing. Roger, my guess would be hazard switch is not doing everything it is supposed to. It is pretty easy to swap out- almost easier than turn signal switch.
 
That is funny Glenn!! I'm going to pursue the hazard switch exchange as a start. Looks like around $37 from Max. Everything has worked perfect since I've owned it, so I guess I'm due for some gremlins!?!?
 
worse comes to worse, you have a spare hazard switch. My guess is someone would be willing to buy it off you if that's not the culprit. Let us know if that was the problem.
 
You can confirm if it is the hazard switch by removing it and shorting two of the connections in its socket. I can look up which numbers have to be shorted. When you remove it see what version of the switch you have (how many contacts).
 
Thanks Arde! I did a search and found this in a post of yours a couple of years ago:

"You can unplug the hazard switch and short its socket connections 49 and 30. If the turn signals work then it was the switch."

I'll give that a try tomorrow.
 
Ardy´s reply a few years ago

Yes. That is the reply that was referring to. Remember the wire test between 2 contact pins, and how the turn signals then worked again.
Another example of how useful this board is (and how much more difficult life was before the advent of the Internet).
 
Swiss Delivery

FYI - My car was delivered new in Zurich-Dielsdorf and spent its first 26 years in Reinach
Switzerland.
 

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Update

I installed my new hazard switch today, and my turn signals returned. This made me aware of other problems that I had not noticed on this circuit before. I don't have brake lights, my windshield wipers don't work except with the washers, and my Euro park lights don't work in the front.
 
RogerB said:
I installed my new hazard switch today, and my turn signals returned. This made me aware of other problems that I had not noticed on this circuit before. I don't have brake lights, my windshield wipers don't work except with the washers, and my Euro park lights don't work in the front.
Click to expand...

Allright! Let's fix the others now:

1) Brake lights: could be the brake light switch at the brake pedal, easy to pull out and short to see if they work then. I think the ground is shared with the other lights in the rear so your ground is probably fine if the other lights work.

2) Windshield wipers: could be the switch at the stalk, or the wiring connecting to it. Fuse and motor are obviously OK.

3) Euro park lights: If I recall the diagram the front and rear are the same line, so fuse and switch are exonerated. If the wiring has been tampered with I would think something is not wired under the dash properly, or by chance both bulbs or both grounds are bad in the front.

2) and 3) may be deliberate, you should not drive the coupe in the rain nor park it outdoors overnight.
 
Gremlins

Please clean and check all connections here...
000_0352.jpg

Then run a #10 wire to the back of the car from this point...temporary, outside the car to a good grounding point in your trunk. The wire you see with the blue boot I ran to my ECU under the back seat after testing as noted above, now permanent. Cured all for me. Let me know if this helps. Of note...I have also seen a bad battery (sometimes they "bridge" and although test good as far as voltage goes can cause problems) to be the cause of gremlins. The odds that you have 18 components N.G. is zero.
 
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Arde said:
Allright! Let's fix the others now:

1) Brake lights: could be the brake light switch at the brake pedal, easy to pull out and short to see if they work then. I think the ground is shared with the other lights in the rear so your ground is probably fine if the other lights work.

2) Windshield wipers: could be the switch at the stalk, or the wiring connecting to it. Fuse and motor are obviously OK.

3) Euro park lights: If I recall the diagram the front and rear are the same line, so fuse and switch are exonerated. If the wiring has been tampered with I would think something is not wired under the dash properly, or by chance both bulbs or both grounds are bad in the front.

2) and 3) may be deliberate, you should not drive the coupe in the rain nor park it outdoors overnight.
Click to expand...

1) I agree. That will be my first check.

3) Wiring MAY have been tampered with? {:>) See attached. I will check the console switch also.

2) and 3) may be deliberate. The car has never seen rain on my watch and is either in an enclosed trailer or garaged at night.

I may give the external ground to the rear a shot also.

Thanks for the input!
 

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Check washer stalk switch for the back plate being crimped on tight (it may move as you push/pull for wash)...after years of use the back plate can loosen and allow a connection to fail...bending the crimp/tabs into the unit can tighten them back up. Might as well check the turn stalk as well.

The front euro parking lights have a ground up front, make sure the connection is secure.

Jon
 
Nice pictures! Please clarify which one is before vs. after :).

You are right, tampering is not the word.

Good luck.
 
Gremlins

The reason I mention the battery is because a couple of years ago I had a relatively new battery short internally on my 'benz. Pretty devastating results. I have seen quite a few batteries (brand name) of late that have failed prematurely. Poor quality control / manufacturing. I now use Optima for all my personal vehicles, worth the extra $$$
 
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