1992 Radio Wiring Problem - HELP

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

[XBAJBUSX]

get the wire harness from crutchfield it is much ez then cutting the wire it plug and play operation

[BgDg3086]

What XBAJBUSX said is true. If you don't use that way you have to test each and every wire. The Power is on the Black plug though Speakers on the Grey