Why won't the driver's side seat belt in my 2012

SOURCE: scion xb wont start

Hi.. Yes i fix my problem by disconecting the neutral suitch and reconecting it ,,they get dirty with time and dont make contact ,Is a good idea to disconect and clean as many contacts as you can and put some special grease on them to prevent other problems ...

SOURCE: need help to remove 2005 Scion xB water pump

1st ...that should be covered under 6 year 50k power train warranty from the dealer.
But if your over....you need to unbolt the right side motor mount (on the water pump side) and lift the engine some with a floor jack to get clearance,

SOURCE: power door locks, scion xb 2005, drivers side.

replace the remote key battery.

SOURCE: Remove 08 Scion XB Navigation

The trim around the stereo and center vents pulls straight out. It is held in by plastic reusable clips. No tools needed.

SOURCE: How do I install alt. belt on 2005 scion xb?

I just looked at my '04 xB. It looks very straight forward.
loosen the bolt that holds the alternator to the bracket.
carefully slide the alt to the bottom. (Also be aware of the plug and wires on the alt.They should never hold the weight of the alternator. You dont want them breaking prematurely.)
Pull the belt off, remove the belt from the crank shaft pulley.

Do the reverse, and you will have replaced the belt.

Make sure to check the belt in about a week or so.
New belts will stretch over time. Make sure you keep the tension tight enough to work correctly, but not so tight that the alernator shaft is warped.
I usually place the new belt on both pulleys and give a good "medium" pull on the alt while tightening. Find the middle of the belt and squeeze them together, depending on the type and length of the belt, there should be about 1/4" of flex on both sides.