Turn the dial to Ohms and place the probes on the pos and neg leads. Keep in mind that it would probably work out better if you removed the subs and placed the probes directly where the wires connect.

I have talked to a ton of people and most everybody says go with the JL SB and be done with it. You will have to add a sub amp however. Did you retain any of the factory stuff besides the speakers? or were those changed out?

I dont want to go through the hassle of changing out everything like I did on my e39 so im just gonna get some summing devices and build from there.