I've been messing with the tach amp for a few months as many have...tried cardboard, plastic disks, even thought of taking up smoking so I'd have fresh cig butts available LOL. Anyway, tach stopped working totally. I'd rather repair the part than just replace it - there would be some satisfaction in doing that. Anybody ever try? Is it too big a hassle? Anybody buy the $58 shipped one on ebay? (the dealer wanted $265 and could get it in 4 days - WHAT A PRINCE!)

If extra pressure with cig butt makes it work a little longer...is the failure connection related? Like in mine pictured below...some of the black wires have lost insulation...could replacing them fix it? Or is the failure more likely a capacitor, resistor, etc on the small circuit board? Thanks, Doug

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1983 300SD 307k miles
1993 Ford Escort Wagon 215k miles
1995 Isuzu P'up 214k miles

Only a guess but, since all the other electronic MBZ components of this vintage benefit from a resolder, the problem might be nothing more than a cold/broken solder joint. I wish I had the spare time to dissect that amp and remove all the potting to determine if a resolder would do any good.

Also, take care when doing the cig-but trick. I tightened mine too much and broke the amp circuit board.

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Never a dull moment at Berry Hill Farm.

I resoldered the circuit board on my 300D, and it was rock-solid ever after.

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- Nate

'85 300SD (200 kmi), Running on Biodiesel
'83 300D (230 kmi, RIP)
'80 300D (150 kmi, Foster Car)

I tried soldering, etc. Eventually, I just gave up after multiple tries. Some of these are just beyond repair. Hopefully that's not the case with yours.

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Paul
2004 E500 4matic; 72,000mi

I stuck a plastic worm under the bottom of mine. I also used cig butts, foam peanuts, cardboard etc..... Plastic worm I guess does not compress as fast and keeps the pressure on it so it works. Is the piece you all are talking about soldering inside the cap? If so, I would love to fix mine the right way instead of keeping Bass Pro shops in business!

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2005 Accord Hybrid (Wifes)
1995 Subaru Impreza L AWD (Snow car)
1984 GMC Sierra 1500 (Mine)
1983 300CD Best $ I ever spent. (Mine)
1984 190D (sold and glad I did)
1983 300D (sold and wished I hadn't)

I'd like to come up with a replacement system and do away with that tach amp arrangement or design and build a replacement component for the 'amp'. The thing is strange in that, from the 83-model wiring diagrams, it appears that voltage goes to the analog tach gauge and that the ground from the gauge is switched by the 'amp' to operate the gauge.

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Never a dull moment at Berry Hill Farm.

Jeremy,
The part in the pic is the guts of the black cylinder tower with some gel pulled away. The circuit board is that pumpkin colored wafer neat the top of the pic - wires, caps, resistors are soldered to it.

I'll try soldering the circuit board as ya'll suggest...can't hurt...don't work now.

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1983 300SD 307k miles
1993 Ford Escort Wagon 215k miles
1995 Isuzu P'up 214k miles

Thanks dougand3, I will give it a shot this evening and post the results as well.

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2005 Accord Hybrid (Wifes)
1995 Subaru Impreza L AWD (Snow car)
1984 GMC Sierra 1500 (Mine)
1983 300CD Best $ I ever spent. (Mine)
1984 190D (sold and glad I did)
1983 300D (sold and wished I hadn't)

Happy my diesels don't use a tach amp! I <3 '85+ cars.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

please corect me if im wrong,but, if its the thing on the drivers side wheel well, u can find them for about 90.00 bucks

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82' 300SD

That's where they are at. $90 is pretty steep for them new.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Ebay Seller has them for $58 shipped. But that's too easy...gotta try to fix it.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=005&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=150045308179&rd=1,1

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1983 300SD 307k miles
1993 Ford Escort Wagon 215k miles
1995 Isuzu P'up 214k miles

Hey, there is nothing wrong with an easy fix!! Sometimes we forget.......

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

List on the RPM sensor for 82-83 models from WorldPac is $230something and Phil sells it for $145. Why is this eBayer's part so cheap?

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Never a dull moment at Berry Hill Farm.

"These sell for nearly $40 at the local dealer"

There is the problem. Smoking too much crack!