I am replacing the stock radio on my 1992 grand marquis GS with a JVC KD-SX990. Couple problems:

Which wire is the battery lead to keep my presets, etc?

The clock is now off, need to join 2 wires?

With the lights on, adjusting the interior dimmer shuts off my new radio.

Can anyone help with these problems, or provide me with the 1992 wiring diagram? Thanks in advance.

Joe