Here is the description how to modify the Delco-Bose radio model 16041551
to 0.05 MHz steps on the FM band. This is useful in countries other than
the USA, where radio stations aren't on odd-tenth megahertz intervals.
remove the upper cover (3 screws)
remove the 5 screws holding the first PC board.
gently lift the PC board.
locate two diodes (1N4148) between display and IC labeled "DM 246 DQ
7815D" (28 pin) on the second PC board, now visible.
there is spare place for another two diodes. Add a diode to the
location closest to the above IC. This can be done in two ways:
Remove the bottom cover and the cassete drive, clean the
soldering pads from solder. Solder in the diode and reinstall
all removed parts.
Do nothing of point 1), but solder the diode across the IC
mentioned above. Anode to pin 10 and cathode to pin 26. (This
is much easier)
reinstall PCB and cover.
If you are not familiar with radio electronics and soldering, ask a
friend to do the modification, who is.
P.S.: All the 4 Diodes enable/disable special functions. It's interesting
to find out what every diode does. One disadvantage: Installing the diode
no. 4 sets the steps to 0.05 MHz, but shortens the upper FM range to 104
MHz (sorry).
When installing an aftermarket radio, use a harness that adapts
to the harness already in the car so you won't have to cut off the
factory plug.
This installation below applies to people who use the factory
harness adapter.
Relays are normally numbered 30, 85, 86, 87, 87a. They are marked on the
relay.
On number 30.......wire to Battery +, or constant
On number 85.......wire to Ground
On number 86.......wire to Power antenna input on the radio
On number 87.......wire to Power antenna input on the harness adapter
you will notice that on the other side of the
adapter on the factory harness, that there is
two pink wires that go into the plug, these are
the wires that turn on the subwoofer.
On number 87a......no wire
For people who cut off the factory plug, just splice the two pink wires
into a wire and plug it into number 87 on the relay. All other wires are
the same. That should get ya all started!