Round thing with electrical connections mounted on the driver's side fenderwell, under the hood.
Thanks

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

that's the diagnostic port

xp

If you're talking about your '83 SD, I beg to differ with xp190. There is no diagnostic hook-up on your car car. The part in question is the "tach amp". If you remove it, the tachometer won't work. If the tachometer doesn't work, that part is a common cause for this problem.

Yes, this is from the 83 300sd.....
How can there be a diagnostic port when here is no ECM?

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

sorry I was only going on what I know about my car

xp

It diagnoses RPM.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

yep in my old 300SD this little jimmy came loose a few times and I had to tighten her back up to get my tach going.

__________________
Brandon



2008 S550
1957 Dodge D100
1967 VW Microbus 21 Window
2001 Suburban
2004 Beach cruiser bicycle
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