Making Aux electrical connection

Truckers live and die by their power inverters, mine was one of the most important purchases I made. So I have some first hand knowledge in the area. Questions before answering: How big an inverter are we talking about? What do you plan on running with the inverter? Do you need to be able to use it when the engine is off? What is the "wave" style of the inverter? Square wave inverters tend to mess up what ever is plugged into them over a period of time. This why the manuals that come with them tell you not to use them to charge up anything with internal batteries that doesn't use an external power supply.

Whitelightning

If the inverter isn't too big you already have a couple powered connections in the little panel under the dash.

Its a 500 watt inverter. It comes with two cords, one is a Cig lighter cord in which the mfg says to only use this if the expected load is less than 100 watts. The other is a pair of aligator type clamps made to clip on the battery. Hence the need to run wire to the 12v stud. Yes I would like to use it with the ignition off. I noticed that the aux plugs in the truck are always hot. I have a gps system hooked to my laptop in which traveling down the road, would need the battery charged from time to time. The laptop requires 162 watts at the input, (120 @ 1.6 amps) not that efficient, as the output is supposed to be 19 vdc @3.42 amps. The style is called 'Modified sine wave" meaning stepped square wave instead of a full square wave. TIA

Well 500w/12v is well over 40A. The always hot SEO pin is a 30A fuse as well as stud #2. Stud#1 has a 40A fuse so its the closest, looks like you will have to pull a wire.

Eugene....thanks for the answer. My original question was, do I have to pull the metal brace from the fender to the cowl in order to remove the fuse box??? How do I know which pin is the SEO and Stud #1, #2 etc. As mentioned before, my cig lighter and aux1 and aux2 plugs, (under the little cover) is fused at 20 amp. Mike

Duh!!! 1.6x120= 192 watts in to make 65 watts out (19x3.42) Mike

yes, the metal brace comes off then the cover just pulls off, there are tabs at the bottom you just pull the plastic outward a bit. Stud # 1 is at the front of the box and stud #2 is at the rear. If you feel like doing the work you can feed a wire through the harness through the firewall with the rest. You will have to unwrap some tape and retape when your done.

Not very efficient at all, usually switching power supplies are better than that, are you sure one of those numbers isn't the max? Is the laptop all your running, why not pick up one of those little inverters just for it. My Latitude is rated at 30W but my wife's crappy Inspiron with its hot desktop cpu will run off a 70W inverter just fine.

I have to assume that they are the max, just reading off of the "brick" in the middle of the ac cord to back of laptop. I had posted a question in the laptop NG asking about this and after several discussions, I felt this was the best solution not withstanding dealing with all the cords etc. since I will have the capability to run other things. I did notice that some of the laptop converters for my particular situation only provided 15vdc instead of the 19.2 volt and they were x2 or x3 the price of the inverter I have. I am sure that the voltage is further regulated down to what the battery actually needs inside the laptop. Battery rating = 14.8 v -