I lost the cover to my fuse box and i think my fuse has went out in my air condition and i need to know what number is the fuse

Fuse box is located behind the left headlight. Fuse diagram is on the fuse box lid underside.

How to check and change fuses Toyota Yaris Year models 2006 2011

The owners manuel should have a diagram of the fuse box.

Go to your local auto parts store and check the mannule for your cars make and model.

if you look inside the fuse box cover llid you will ba able to know exactly where it is located and what size it is.

Usually a small flat screw driver wedged under the plastic covers should help you pry it open.
FYI If a fuse blew it went for a reason. ( old age on a 3yrs old car isn't a reason).

Try finding a cover at a wrecking yard
or...use a test lite, to check the fuses.
You can find one at the autoparts store.

First of all; what you are doing now is very dangerous for your car & you could put your car into fire.

Second; normally the car's service book "booklet" comes with the car should “must” come with it, normally has a page which has the fuse drawing or layout which indicate the fuse locations & or its ratings, i.e. 10 AMPs for cigarette lighter
( just example don't take the figure for grantee" But if the load (like air-condition) is high load it must be rated high .
Another example: Engine DC starter " It draws very high Amperage and should has very high "fuse" rating could be 60 AMPs fuse or relay.
to now more about electric & electronics go to a site called
" autoshop 101 . com"
I made spaces between the name, numbers & .com; because
the policies of some sites doesn’t allow you to put their !!!!!!!!

What about buying it from junk yards?????

RAM,
Earth.

One suggestion. Have you checked the fuses ?

I would check the AC or blower fuse to start with. If you have the drivers manual it will show you where the fuse box is. Typically there are at least two boxes to check. One in the Engine compartment and one in the passenger cabin.

Look inside the lid of the fuse box to see which fuse may apply to the AC circuits or the blower and check to see if they are blow. the metal link between the two posts that plug in. If the link is missing you need to replace the fuse with one of the same rating. Make sure you know where you took the fuse out from and put it back in the same slot if its good. Check all the main fuses if possible to see if any have blown and replace if they have.

there is a loose ground and or wrong size fuses for the air
if loose ground you will want to have a certified mechanic trace the grounds back to source
i dont think it could be relay but there is a way to check this
find the relay panel in the engine compartment open it
find the relay that says air conditioning
pull it out
now there are numbers on that relay
in that same relay box theres relays about 6 to 8 of them that look similar to the air conditioning relay
this is where the numbers come in if the numbers match switch with other relays
mark the air conditioning relay with black marker or nail polish so you know which relay is which
if its the relay thats bad the new relay from the relay box put in its place will work fine
put the old one back in the slot where you took out the other relay out of and then proceed to dealer to purchase new relay for your vehicle if the relay was the problem