Dash lights fuse blows immediately.
 

1989 XJ 4.0 4x4 auto 102,000 miles.

If I replace my dash light fuse and turn on head lights it immediately blows the fuse and lights go out.

And also when I have the head lights on at night both my turn signal arrows are faintly lit in the dash. Don't seem to be lit outside at all but it could just be so faint I can't tell it.

Not sure if these are connected. Just looking for some guidance on why that fuse is blowing inmediatley. Been like that for about 2 years and I kind of miss my dash at night hahaha.

May be caused by a short straight to ground down stream of the head light switch or right at the switch itself. I would pull the instrument panel and see if it blows after that. If not, get the voltmeter out with the headlight switch off and start checking wires for continuity with ground. If the fuse does not blow with the instrument panel out then the fault is likely inside the instrument panel or its connector. You'll need to have the wire diagrams to see the connectors and components down stream from the switch. If you look at the back of your instrument panel you may be able to see where the problem looking for any burnt or discolored areas in the flexible printed circuit board that connects all the lights. The goal is to isolate the short to a specific section of wire or component. Hopefully it is obvious and an easy to fix issue. As a former avionics tech I know chasing shorts is not fun.