OBD11 diagnostic tool

Although you didn't say, I assume you are plugging the OBD into the lighter for power. If not, then it isn't the fuse as your OBD port does not input or take any charge from the port itself. If you are plugging it into the lighter than it is possible you are overloading the circuit, thus blowing the fuse. However if that is the case, either you have add on accessories running on the same circuit as an unaltered lighter circuit has built in reserve capacity. Does your lighter element work properly when plugged in as that's when the circuit gets it heavy load. It draws nothing when the element is not being heated unless other add on or factory accessories have been put onto its circuit. Goggle and you should find a wiring diagram and see what else may be on the circuit from the factory. If there The lighter circuit is a common one to use for add ons as, in most cars because it can be a power always on line or a switched power line depending on the car. Plus it is usually very accessible. If your lighter element isn't working, you might have a damaged receptacle that is causing a short when the OBD is plugged into it or another device is. I would also check to make sure you have the correct fuse, blow clean the fuse box, and try to check for any corrosion in the box. Do not be tempted to put in a bigger fuse as that will cause you bigger and smokier problems. If there are other factory items on the circuit, make sure they are working properly, correct bulbs, etc.

It's the cigar lighter fuse, and what else is drawing power on that circuit to cause the fuse to blow, should be a 20amp fuse.