Battery Replacement Assistance

So when testing for parasitic draw, do I connect the multimeter to the battery? If there's parasitic draw how do you know which device it is coming from?

You don’t know where the current is going and risk damage to the meter. I lost a range on one of my multimeters when checking a lady’s car that way. The draw was a few mA until she leaned on the car - her under-hood light went on and the meter went off.

Now I always use a DC clampmeter to measure current. No chance of damaging the meter on an RV, and the measurement is nearly as accurate as a multimeter.

It is possible to detect a current going through a fuse by measuring the voltage across it. Zero current will have the full battery voltage across the fuse. If there is a smaller voltage then check the current with a current meter.