Quote:

I,m reading 12.55 volts between the negative cable and negative post. I assume this is not normal?



this is perfectly normal ,the reason you are getting this reading is because there is a current draw with less resistance than the internal resistance of the meter. what you are creating by doing what you are doing is creating a circuit that is a called a voltage divider, and there is no way I'm going to explain it in a post here.

you need to be concerned with the current draw you are getting with the meter connected in series and in amp reading mode.

your reading of 40 milliamps is normal for a car with any type of electronics or an electric clock in it.