Originally Posted by beermc00

I want everyone to know that if your car uses this style of Tach Amp, Techguy's (Bob's) replacement will probably fix your tachometer. He sent me instructions on how to do a few easy electrical tests with a multi-meter before I bought it because I was sure that my 1983 300D was going to need other parts to get the tach working again. Reason being, I attempted the trick of putting a washer shim on top of the old amp and that blew my #8 fuse and then the amp and the plug it goes into smelled like burning electrical wires...not good.

After my car passed the three preliminary tests Techguy emailed to me, I bought his part and installed it in less time than it takes me to check my oil and the tachometer now works perfectly...plus that self-test, sweep thing it does while you are waiting for the glow plugs is pretty cool.

Thanks for reading!