After using a 12V cooler my power socket is out. 

I’ve checked fuse ”44” as stated in the manual but it’s ok, tried with a new one but no luck. 

Checked all the normal sized fuses but can’t seem to find any blown fuses, any suggestion?

Have you tried another device is a phone charger 

 

What amp was you cooler box 

I have two USB-charger that both work in our other car. ☹️

Not sure about the amps, built in fuse is rated 8 amps, 46w in specifications.