The radio will not keep it's time and the nav won't keep memory of what state your in

check fuses and connectors

XL7 not XL-7 (the dash matters big time)
i'll guess its a dash.7
REDUX
in your post you said fuses are good (tested too)
have you checked and reseated the connectors on the OBJECTS that fail>?? (that is free to do)

we now learn many things fail on car,
even HEAD LIGHTS?????
and no statement of what works. in total!
does car drive perfect night and day?????
just a clue here, and win big. huh>?

I can't drive your car and see all those many things failing,& that are. ok .. and what does not fail....

but this car has CAN-bus (or the like)
a NETWORK for sure, and bus structured.

and does not work like some 1990 Vitara.
at all, not even close to same. (forget them...)
it's a BUS system.
each switch you throw sends a command on the bus.
it's failing I bet because of communication errors
that you fail to see because you did not use a real scan tool at the time of failure.
it must be scanned while failing !

cant fix it if its not broke,...(unless you drive
scan and log data. like i do all the time for all intermittent of any kind....)



does it fail engine running?
is running battery voltage at 13.3 to 15vdc
if voltage is low all computers in car will go nuts. (same with your cell phone)
this is a fact and what i check first?
valid battery voltages first.
2nd after fuses, (done already)
then scan it. using a real scan tool
not some relic.
a real tool can see all CAN buss errors
U codes top the list.

P1,p2, p3 and B codes too.... all seen.
failing.

you can buy tools
rent tools
or get the car scanned failing at any ASE shop.
car parts store may have junky or relic tools.
(i can name 10 that are)
some tools only do old federal P0xxx codes. say some old 1996 tool.

try a real shop and win. really
http://www.ase.com/Landing-Pages/Car-Owners/Find-a-Repair-Shop/Shop-Locator.aspx

in the USA,
there are 3 ways on all cars.

1. press reset on the scan too.
2. pull battery neg lug, and lose the radio , and nav. codes,
3. pull the ecu memory fuse. (no engine stated, so can answer)

I think you will need to access the Nav System with a professional
scanner or scan tool & then use manufacture trouble charts, to even know what the system is supposed to do, & how to diagnose it

Hopefully a repair shop, if they want the job,otherwise blow out
your wallet at a dealer

I am afraid that you are out of luck. Did you check the fuse. The only other person would be the dealer or you may find another unit in the salvage yard.

The first thing you want to check for is the brake signal,without this signal it will not crank,this is the easy one make sure you get brake light,the second is to have the starter tested by a direct method,this gives the indication of the health of the starter

The fuse is made to protect a 10amp draw 13 amps will start burning wires you need to follow the specs if your 10amp is blowing then there is a circuit prob.

I have run into this problem many times on your particular type of radio. I have worked in a gm dealership for years. Sometimes we can reprogram them and they work better, but all will eventually need replaced. The cheaper option is to have an aftermarket radio installed, for the price of a new factory radio, you could have a much nicer aftermarket unit.

Check Fuse 2.3 (20 Amp). See electrical diagram below.

When it goes, it'll take out the audio and "Cluster and Panel Illumination."
(assuming your vehicle doesn't have an OEM Nav system - in which case fuse 2.3 would
supply power to the Nav system).

Fuse 2.3 is located in the CJB (Central Junction Box) - not the BJB (Battery Junction Box),
nor the AJB (Auxiliary Junction Box).

Also, check fuses F1.6 (60 Amp), and fuse F1.62 (30 Amp) in BJB (Battery Junction Box).
Also, check fuse F2.17 (15 Amp) and the "Accessory Delay Relay," both in the CJB (Central
Junction Box).





Here's the electrical diagram for 2005 Mercury Mountaineer Power Windows:
Note how fuses F1.6, F1.62, F2.17, and 'Accessory Delay Relay" will all
disable the power windows.

I have experienced many electical demons with all my British cars. The nav units can and do fail. I had a goofy one this summer and the only way it got fixed was to replace it. The module not the head unit