A while back my odometer stopped working as well. I ordered replacement gears from odometergears.com, installed them and it worked OK for a while.

Then it seemed it would work sometimes, then not work anymore. I inspected and lubed the gears a couple of times with no real change. Recently the odometer stopped working all togather. I found this thread and embarked on fixing mine as well.

The gears I installed were working just fine as I can sping them and the odometer moves fine, which makes me believe I have an electrical problem:



Using some solder wick and a good iron, I unsoldered the five points that hold the speedometer to the unit:



I found this:



Unlike the OP, my 85 300SD only has two capacitors. One I can clearly see as 220/6, the other one I can't make out for sure, but I beleive it is 1.7/16. Does this seem right. I know very little about these. I plan on picking some up at radio shack over lunch and putting this back togather.

Any good eyes here that can make out the numbers on the smaller cap?




Thank you in advance!

__________________
----Adam

1985 300SD 322,000

To me it looks like 47, which would also make sense because that is what the others had, too.

RadioShack might work, but I liked the 105C ones I got from a real electronic shop. RadioShack has them online, unless you have a RadionShack with a huge selection nearby.

Hope that works!

__________________
89 300 SE Euro (264,000 miles)

I would guess 47 too.

I repaired an 86 300SDL speedometer and it had a 47 uF cap in it. 47 and 220.
W126 Speedometer Repair - Imgur

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82 300SD 145k
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My '84 300SD only has two capacitors: a 220uF and a 47uF also. It looks like the markings on your capacitor are stamped off-center resulting in the side of the "4" not showing up. Funny, though, because it does look like a perfect "1".

__________________
1984 300SD
351,000 miles

Thanks for the confirmation on the numbers. I was able to pick up both caps during lunch, a 220 and a 47 uF 35w. I'll get them soldered in this afternoon and get a test drive this evening.

I do have some nice test equipment here at work and I am curious how the old ones measure when I get them out.

__________________
----Adam

1985 300SD 322,000

Hmmmm.


I got the new ones soldered in:




I used these radioshack part numbers:




I took the old ones, and with a BK precision 875B meter I found that both of the original caps measured pretty close to what they should be. The 220 uF cap measured 232 and the 47 uF cap measured 46.

I'll get this assembly back in the car this evening and hope for the best. If this does not get my odometer going, what is the next item that could be the culprit? I do have new gears and when I spin the drive gear with my fingers the odometer does move fine. Could the motor be bad? Can you replace that?

__________________
----Adam

1985 300SD 322,000