1982 300CD, US

I removed the cluster to jump the rheostat. After putting it all back together the electronic on the left side don't work. (Fuel and engine temp) Of course, the oil pressure works since it is mechanical.

Is there anything peculiar to those two gauges?

Ground is the common point between the two. I would take out the cluster and check over the connections and the circuit board for obvious issues.

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OK, I'll do that. Thanks for the tip. Now that you mention it, it makes sense that a failed ground could be the cause. Has anyone else seen this particular problem?

Did you disconnect the battery before removing the instrument panel? If not, you likely fried the circuit board (been there, done that). You can look for burnt traces on the circuit board. In my case, it was under the gauge itself.

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1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

Many of us that have experienced a grounding failure repair it by simply running a wire from the back of the cluster to the ground point behind the dash. Look for the cluster of brown wires.

In my case, I put a quick-connect in the new wire to simplify future cluster removal.

I didn't disconnect the battery. I hope I didn't fry anything. I'll do the grounding wire Rocky suggested and hope all is well. Stay tuned

Typically, those gauges are powered (12V+) from within the group, and the sending units (variable resistance) create the ground connections.

If Frank is correct about the left side gauges, grounding the frames of the gauges won't do anything and my problem is still unsolved.

Worked for me. I don't think the gauges care where they get the ground from so long as they get one. If your problem has it's source in an existing faulty ground connection, the new wire will fix it.

The variable resistance that Frank refers to provides the indicator values (needle pointing position). A fixed ground is still needed as a reference.

Use a clip lead to check it out if you wish before you do any wiring.

BTW, I have removed my cluster probably six or eight times by now and have never disconnected my battery when doing so. Maybe I am just lucky but I don't think there is anything back there that can be shorted while the key is off.

It was the fuse! I checked it first. Did other repair work. I probably tripped something while doing the other work. Then I didn't check the fuse again before posting on here.

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I have a 1982 300CD US with a non functioning Tachometer and clock. Are there common causes for this failure?