I need to measure current in a small electromagnet powered off 3 x AAA batteries in series. This is the manual for my multimeter. When I run this multimeter in series and try to find the current, the electromagnet doesn't work anymore. I suspect the internal resistance of the multimeter to be too high compared to my electromagnet (just a few coils of 20AWG magnet wire) so the electromagnet isn't getting enough voltage anymore. Is there a cheap/free solution for me to find the current in the electromagnet?
You should use the 10A range. Set the meter to 10A and plug the red lead into the 10A jack. There are two fuses, one 10A fuse for the 10A range and one 250mA fuse for the lower current ranges. You may have blown the fuse for the lower ranges. The fuse replacement instructions are on the last page.