I had been having turn signal flasher problems for some time now on my 300D 1976 W115.

Since the flasher relay for the W114 and W115 is no longer available new I was able to purchase from NAPA a solid state #263 flasher ($16.99) and adapt it to work in my 1976 300D. The original flasher Bosch 0 335 200 007 was flashing too quickly and I even attempted to resolder and repair the flasher with no luck. Used ones are available on ebay etc for $40+ but you are taking a risk that these would not work either.

I had read an article that said to buy a NAPA NF550 3 prong unit but NAPA has discontinued these so I bought the #263. It is 3 prong but I found that you only need to use the 2 prongs labeled X and L (the prongs face each other) and solder short wires with bullet connectors on the ends to plug in to the original base. As I found out the third prong is not needed and will only short out your fuse when connected so I eliminated that wire. Plug the 2 connectors into the original base holes labeled 1 and 3 in your car.

The flasher works great now flashing at the correct interval for both the turn signals and the emergency flasher. I am pleased to have a new unit for only $16.99 instead of $40+ used. Pictures attached..

I hope this helps someone with the same issues I have run across.

John

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__________________
Western NC
1987 300SDL W126 Turbo Diesel 335,000 + miles
1976 300D W115 275,000 miles+

Thanks John for the info and motivation to solve this with cheaper over the counter parts.
I used a simple 2 terminal flasher, a couple spade socket lugs and a couple 5/32 bayonet lugs.
I did it on a 74 450SL (107)

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Where did you purchase the bayonet lugs?

Because my daughters 1976 300D flasher relay failed, and I was considering this option.

Happily I found a replacement on EBAY.

.

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good work. if anyone else needs to fix too-fast flashing, the cause is deteriorated electrolytic capacitors. as i recall, there are two. i got $1 replacements from radio shack.

__________________
'77 240D, 504H, OM617.952, etc.

Thank you gentlemen. It's kind of entertaining when one bulb goes out and it turns into a strobe light. But I need to address this.

Hello to all,

I realize this thread is quite old, but since I have benefited from the information shared here, I thought I would add my solution to finding an economical replacement for my defective turn/flasher relay. So, here it is: I discovered that relay P/N 111.953.227 D, as found on many VW and Audi cars is quite suitable as a replacement for this application. As mentioned by others on this thread, it requires the making of short leads with female blade connectors on one end and bayonet connectors on the other end of the leads. The labeled pin numbers of this replacement relay match those of the original relay, which are: 49 - 49a - 31. Simply insert your newly made leads into the corresponding holes of the relay base -- NOTE: it is imperative to carefully identify and match the original connecting pin holes, or the fuse will be blown! Connect the wire leads to the relay blades being sure to match them to their corresponding numbers on the replacement relay. CAREFULLY identify these pins before inserting the leads into the relay socket! The referenced replacement relay is easily obtained from any number of sources. I found mine at a pick and pull salvage yard. The cost was minimal and I also obtained a few doo-dads that were missing on my car while I made the rounds at the salvage yard.

I hope this is of some benefit to others.
Cheers,
Rick C

I just solved this for my W115 (1976 240D) that had non-working flashers when I bought it. Since this thread is a bit older (though still very helpful) and parts availability changes, I figured I'd share my solution.

• First off, after locating and removing the existing flasher relay (which unplugs quite easily) it was obvious that the flasher relay was the culprit of the problem, as I think the pictures show rather clearly
• I was able to find both units that John mentioned in his initial post. But I was hoping for something closer to the original unit, ideally with the same 3 pins (31, 49 and 49a) for an easy swap-in.
• Also at napa I found the Flasher Relay ATM 111953227D for $7.49, which had the desired pins and appeared to have the same internal design (see pictures of the unit and the circuit diagram from MB manual). On top of that both the unit I pulled out and the picture of the napa unit read "2/4x21W".
• Installation was a breeze: I just cut off the old bayonet style plugs and after a quick test I crimped on the correct size spade plugs, connected them to the unit and finished it all up with electrical tape.

Signal and hazards are all working again at the correct speed!

Hope this helps anyone needing to replace the flasher relay on their W114/W115.

Hans

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