gauge cluster help

[windstorm]

I have a 1979 Porsche 928 with multiple gage cluster issues. Current problem I am working on is fuel gage either shows full or empty, no in-between. I checked sending unit and did see varying voltage as I moved the float but no change of the gage either full or empty. I now have the cluster disassembled and I see that black spool with wire wrapped around it looks like it got hot and some plastic melted. Does anyone know what that does? It looks to me like some sort of magnet or something. I was wondering if there is a way to bench test the gage and see if it could be isolated to the gage or the wiring.

Thanks,
Mark

[medipedicman]

I don't know the answer to your specific question but I can tell you that over the years I have solved many problems in the cluster with cleaning all of the connections and re-cleaning grounds. I pulled a spare off the shelf from a 79 auto after reading your question and I tried a multi meter with no results and then a 9 volt and alligator clips with no reaction from either.