My 82 300cd has an intermittent brake lining warning light.

I just had a partially seized caliper, so I rebuilt both front calipers, replaced the rotors, pads and sensors, and used dielectric grease on the clean/dry sensor connection to the harness

So no it’s not worn pads, no it’s not bad sensor leads. It’s something else.

And it’s the yellow lining light, not the red brake light.

I’ve gone through this:

W123 dash brake warning lights, a review

Wires look good, connection points look ok.

Makes me wonder if it’s actually the cluster.

In the link above, it looks to me that the charging light and the lining light are isolated by a resistor. I assume that’s to allow for redundancy in the alternator excite circuit. Could that be a clue? Charging system works fine on this car.

Anyone have any other experiences troubleshooting this light?

I assume perhaps disconnecting both harnesses Underwood would help isolate side/location?

Thanks!

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
2008 ML320 CDI (199k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)