94 Jaguar Coupe V-12

I just bought a 94 Jaguar Coupe V-12, I thought I would go through it changing all fluids, new belts, new front brakes, complete new greasing etc. Ever since that I have had electrical problems, dashboard lights not working, rear tail lights not working, intermitant lighting of check engine light. What did I do wrong? and what can I do to fix it, or do I have to take it into my Jaguar dealer? Any suggestions out there would be appreciated. THANKS!

Obviously, you realize that the components you worked on were not electrical/electronic in nature (belts, fluids, etc.)..........this means that you likely moved/touched/disturbed something while involved in these projects.

When I was a little kid, and I lost something, my Mom would always tell me to "retrace my steps" (didn't everyone's Mom say this?)......you've got to go back and see if you unintentionally disturbed anything.

You may also need to spend time with a DVOM (Digital Volt-Ohm Meter) and the Jag wiring diagram.......this can be a long pain-in-the-neck process, especially with intermitant problems.

I'm including a page that may give you some ideas (you may have to register for some of the contents):
https://jaguar.professional.org/index.php

I'm not a Jag person, but I'm sure there are many folks here that would like to hear what you've found out....that's what this forum's all about.....please let us know what the results of your efforts are. Also, welcome.