Have you wired it in yet ?
You should decide where you want the meter to fit, then and more important you should decide how you are going to run the cable and what cable you are going to use, or are you going to fit it near the battery, is you battery under the passenger seat?
As I said earlier you don't want to be running cables around the MH, it causes volts drop in the cable and you end up have to use thicker wire because of this. So I don't know how good your DIY skill are. I would say that fitting it near the battery on my vehicle would be the best and easiest option on my MH, but difficult to see it when down by the seat. So that is the easiest way to connect it in unless you want to cut into the main wiring by the electrical box, (dependant on your vehicle which I don't know), I could do that as I was an Auto Electrician, so pulling the box apart wouldn't be beyond me. But the better option would have been as I thought I broached earlier was to buy the slightly more expensive meter that had a separate shunt.
But you have it now, if you don't feel confident in fitting it you should get a professional to fit it for you, you don't want to set you MH on fire. I've seen it all before. If you do it yourself disconnect the - side of the battery first and that should be the last connection you put back. If I were you I would connect it using your existing wiring by cutting into it + & + and connecting that then - & - and connecting that. With your meter you would need to use yellow eyelets I suspect of the correct size for the screws, or you could make up 4 short cables, min 30amp cable, with eyelets attached at one end then you could use a H/D screw down connection block, that way you can remove the meter and put the wiring back to as was if you like or to swap the meter around the other way if you needed to. I have a watt meter that is reversed like that for different tests but I don't think you would need to do that with your monitor. As I said earlier I don't know your meter so you need to follow the information given in the instructions and from hairydog in post 61, who has a similar meter. It's basically plug in and play to understand it.
Make sure everything in insulated so it can't short out.