I just did this a few weeks ago with a Clarion.

Radios these days work backwards. They want a constant hot lead and a
ignition only hot lead. It used to be the constant hot was only for the
memory. This new one i bought pulls all of it's current off of the constant
hot (battery) and only uses the ignition hot to trip the relay to tell the
radio it sould be on.

So I added an additional rear-defrogger (hehe) switch to the dash and ran
the ignition hot through it on it's way to the radio. This way I don't have
to reach over to the radio to turn it off (little button) and more
importantly, passers-by at night don't see the clock display and know that I
have a new radio in there.

Mikey
`87 Westy, Eeore

Since my current radio is truly "off" when I turn it off, will my new radio
drain my battery if I hook it up for constant power since, because of the
clock, it is never really off?

Scott Semyan
'85 Westie
Seattle