Hello,

I know very little about electronics so bear with me, I have this DFR0245-G amp meter and shunt and the schematic shows the meter in series with the negative wire can I switch this so the amp meter is in series with the positive wire? I'm just trying to make a small handheld meter for fun to check trailer wiring.

 

Yes, you certainly can. Connect the positive of the supply to the lositive of the meter, and the negative to the load.

 

I got 1 of those wrong once, it's a wonder it still works. Soon I'll have to take it apart and check it.