Is brightness adjustable on a JVC kd-r200? - JVC KD-R200 Car CD/ MP3 Player

Press and hold SEL (select) for more
than 2 seconds.
"DEMO," "CLOCK H," "CLOCK M," "DIMMER,"
or "AMP GAIN" appears on the display.
Set the hour.
1 Select "CLOCK H" (hour) if not shown on
the display.
2 Adjust the hour.
Set the minute.
1 Select "CLOCK M" (minute).
2 Adjust the minute

Here is the installation guide for a KD-R200. For car specific, you would have to reach out to car dealership

Problem with KD-R200 or KD-AVX33?
What does it mean by "it lights up blue then nothing?" Does it takes CD in?

Hold the SEL button to bring up the PSM menu, use up/down to select CLOCK H for hour or CLOCK M for minute, turn the knob to adjust, and press SEL to set.
Full details are on page 3 of the manual.

trying to set up a jvc KD-R326 does anyone which wires are the power ones?

Here is a manual for your radio.
http://books.jvc.com/Download/177964754/GET0582-001B.pdf

you have the red and yellow wire on the radio mixed up switch them

Here's the manual for your KD-R200:

http://resources.jvc.com/Resources/00/01/15/GET0582-001A.pdf

the settings and adjustments are found on the left half of Page 3 of that PDF.

I hope that works for you.

run an earth wire direct from the battery to the stereo

Press and hold SEL until menu appears
Using the scan button (FWD/REV), select Clock H
Using the volume knob, set the value
Using the scan button (FWD/REV), select Clock M
Using the volume knob, set the value
Press SEL to save and exit