a '87 -' 89 560 V8 at my tech's shop. Note the 'bad oil gauge' hand written on the back.
The pic shows that it appears to be an electrical coil (large white area) with a 'trimmer' coil to set the 'calibration'.
Have not yet found a 'schematic' of it so am at a loss to explain. First one I've ever seen. Looking closely, it appears that the trimmer coil (shunt?) is burned.
Does yours look like this?
The other IC was from '82 Mercedes and it was mechanical with a direct connection on the back of the IC for a line from the engine.
The failure in this one (also bad oil gauge!) was leaking oil!! Imagine the complaint . . " I'm getting oil dripping down my leg. . "!
The oil pressure line directly hooks to the oil gauge and drives a small plunger which works against a large coiled spring to drive the indicator needle via some mechanical step up linkage. Almost like a watch!!!
Good idea except for the direct high pressure oil connection to the back of the IC!!! Could see why Mercedes engineers re-designed that idea.