Cigar lighter in My 1996 toyota avalon cannot work well because my navigator cannot charge when pull inside the plug. my radio is ok and I check the fuse it is in good condition. So I think the problem is the cigar lighter and maybe the connection is not good. I am try the lighter but it is still cold after plug in for a while. I dont know how to open the cigar lighter and I cannot find the screw.

Cigar lighter tends to become corroded and dirty inside so eventually no connection to the heater or power plugs is possible. Check supply and ground from inside the socket with a large wattage test lamp.

If the ground and supply is good and the internal contacts clean it should work as a power socket if not a lighter. Maybe the heating element is u/s.

check out the fuse panel mounted under the dash

On the back side of the lighter there is a fusable link between the incoming power wire and the metal tab that connects power to the lighter. This is a very small wire, bent 90 degrees, between two tabs that are mounted on the same small screw. It looks like the incoming power tab and the power to the lighter would be connected, but they are insulated from each other on the screw. If the fusable link is blown, you will have power at the power connector on the back of the lighter, but no power to the center terminal inside the lighter.

15 amp fuse is blown under dash on right side, pull off the blue/purple cover and check the (tail/dome) fuse. radio is probably not wired correctly.

Battery could be old/weak/defective. Check relay/fuse box around the drivers side under the hood. Look for blown fuse (you can see easily).
Think about corroded battery terminals and especially cables. Very common. Cables may look ok, but may be oxidized and corroded on inside. They let enough current pass for radio, etc, but can't pass all the current the starter requires

chances are the heat from the cigar lighter melted and the a/c switch/wiring,replacement time.......(if you can get a small mirror behind dash to see if its melted you could save yourself a lot of hassle taking all apart).

first check the fuse if the fuse is good check for power at the back of the lighter if power is there replace the lighter assembly

take the lighter out and put your finger inside hole and pull the inside of lighter hole until it pulls out or if tight pry with flat screw driver on the outer lip and when it come way pull of wire and replace

it sounds like you blow up a fuse,check your fuse box,
check your manuel for locations

gl G

inside the cover of the fuse panel there should be a diagram of which fuses control what.

the fuse box is usually on the drivers side by where your feet are.