Hi,
This refers to 2002 and maybe some younger models of Chrysler Grand Voyager aftercare stereo installation.
There are a number of head units out there that will work with these models. However there are issues associated with aftercare installation.

When installing a new head unit the initial problem is sound via the amps, yes amps, as this model has individual amps to the speakers.
The way around this is to use the aerial power feed from the new head unit to be extended and routed to the fuse bay under the bonnet via a bulkhead outlet above the peddles.
You now require a standard relay unit (purchased for around £5.00 or less) connect to the coil side (this may be terminal 85 or 86 any one of these are ok) of the relay, the power antenna lead from the head unit and get a ground connection from the body (simply run a cable connection from the vehicle body the other side of the relay coil, again this may be terminals 85 or 86) This will enable switching on of the power amps when the head unit is turned on and off preventing the unit from draining the vehicle battery when not in use. Via the NBS relay connections for the new replay I found the third and sixth terminal pins under the fuse unit housing directly under the NBS (New Brand Speaker) relay, these relay terminals are 30 and 87 which are the required power feeds to the amps. Remove battery to obtain access and use a meter to check continuity by placing one of the meter pins in the relay slot 30 and 87 the second pin on the plug terminals under the fuse housing to reaffirm the correct cables to use.
I know this sounds long winded but this allows full operation of the new head unit, well, if you wish the stalk controls to work with the new head unit as well you will require a separate module to allow this to happen, available for around £30-45 and requires a cable feed to run under the steering column and a simple connection. Please note that the new head unit has this dedicated wire outlet.

You can use all functions now and if you want at a later date to go back to the old system, every thing is in place to revert back by simply connecting the 22pin connector plug back into the old head unit with no ill effects.

I hope this helps.