Multimeter giving wrong current readings
First, do not ever operate that with the 20A/250V fuse in the 400mA/250V position. Any momentary mistake and you will severely damage your meter. You may have already done that, unfortunately, and damaged the shunt so that it reads very high. Unless the test leads are in the wrong position. 

When you get the proper fuse to replace the one you blew, always remember to connect the meter in series with something that limits the current, and always remember to switch the positive test lead to the appropriate current position and always return it to volts/ohms when done. 

Never leave the test lead in either current position when you are finished, always in volts/ohms.