I have a 1967 Ford LTD with a faulty fuel gauge. The previous owner replaced the part in the tank with no luck. How do I trouble shoot this problem?

. Test all under dash and under hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post252145

. Check and clean all wire connections.

. Check the gauge itself--it may be bad.