Good Evening,

Looking for some advice on fixing my tach and speedometer. Im aware that the are not connected in resolution. I have a 1975 XJC 4.2L.

I have researched the potential problematic issue for the tach (I'm assuming ballast resistor) but, when I was about to dive into it the electrical schematic and what is installed doesn't match up. Any insight would be appreciated.

On the speedometer issue what could possibly be the cause? Is there a typical part that fails consistently for is year?

Thanks in advance.