The tach in my '83 300D is mostly dead. Sometimes it will wake up and the needle will wave wildly for a few seconds. What's the best way to go about troubleshooting this?
Any pointers appreciated....
The tach in my '83 300D is mostly dead. Sometimes it will wake up and the needle will wave wildly for a few seconds. What's the best way to go about troubleshooting this?
Any pointers appreciated....
The tach amplifier is the likely culprit. The pins get loose solder joints and create an open or intermitent connection. It is a black cylindrical canister about 1 1/2" in dia and about 3" tall located on the left front fender well. The simplest fix is to unscrew the amplifier and place a small wad of papertowel in the center between the pins and screw it back down. This creates a forced contact with the solder joints and the tach should work again. I've had to do this 5 or so times in the last 8 years with my 300SD. Let us know if that works. Doug
I reread this post and noticed yours is a 300D in which case the amplifier my be in a different spot than my 300SD. Everything else is the same. Doug
Two garden hose washers have worked best for me.
No need, it's almost certanily yor tach amp and you can fix it with a small rock or the filter broken off a cigarette.
Thanks Doug and all. I've made the modification and will see if that works when the repairs are complete......
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