Adding Inverter

I have the factory Aux battery, I plan on installing a 3000w inverter. The best I can figure out is you tap into the aux battery at a terminal strip located under the drivers seat, not to the Aux battery in the engine compartment?
Any body done this and which treminal under the drivers seat do I use?
I assume they have that Aux battery isolated so you can't run down you main starting battery!
I,am just getting started with RV conversion, so far I have 1.5 foam block insulation in roof, a Coleman 9.3 Polar Cub roof ac and a fantastic fan/vent.
I'll upload some pictures latter. I'm installing a 30 amp shore power, 10 gal fresh water system this week.

I believe you have an NCV3...you could certainly do that (hook cable to terminal inside cab) if the terminal you're talking about is beefy enough to do what you want you want. I would even go further to say to mount your inverter fuse in the engine compartment, closest to the + side of the battery, and NOT inside the cab.

Xantrex recommends a battery bank of at least 400 ah for my 2000w Prosine inverter-charger.

What are you planning to power with a 3000w inverter? Your thread implies a single battery in the bank?

A 3000w inverter can draw almost 250 amps of the 12 volts. This is big current! Your best bet is to connect directly to the auxiliary battery with a fuse within inches of the battery and very fat cables to the inverter near the battery. I will guess that the aux battery is no more than 200 amp hours which means 100 amp hour usable if you want any significant battery life. Assuming drawing 2000 watts this is about 170 amps which means you have only a half hour or so to use your half battery capacity!

The factory battery is a 95 Ah deep cycle. Not gonna last long.

I don't need 3000 watts, but I got a good deal on it. I have hooked up inverters on my boat and our big truck before, I just don't trust the electronics set up on the Sprinter. All I want is just to power a coffee maker in the morning, and a flat screen tv at night. I have a 2000 watt honeywell genrator to run other loads,

I don't know for certain, but you might want to check the efficiency of your 3000 watt inverter as compared to one sized for what you need. The 3000 watt unit will most likely draw more current at rest and may even be less efficient at the relatively low loads than a correctly sized inverter. As I said, don't know for sure and you already have the unit, but it might be worth trading down in size if possible given your single battery bank. Hope this does some good. AP

I agree that the dedicating a small cheapo inverter to run the tv would likely be more efficient than using the 3000w job for that purpose. If the big inverter is not psw it may be of limited use to run non-resistive loads. (Micros, power tools...)

My microwave load pulls down the voltage off my four batteries almost 1 volt while it runs. I'd be curious if the inverter would be able to operate off a single battery. My guess is that an underseat battery would only be 120 ah or less.

I could run a Mr Coffee off my 2kw inverter but choose to use a Melitta drip filter cone instead. Drips right into the industrial size thermos. Similar process as a Mr Coffee but you get more control over "blossoming" the grounds first. Most people ought to transfer to an insulated carafe however they brew. Best thing is the choice of heat source. The camp stove boils the kettle outside or the magnetic induction heats it inside the van. Choice is good when you are managing kw-hrs.