Hello, my first post in this forum. Great info available here, thanks for everyones input.

I just bought a 2008 Dodge 3500 megacab and my one complaint (yes, I know it's a truck...but) is that it has no Aux power port in the back. Looking at the manual, it seems that some versions do on the back of the center seat console, but mine does not.

I want to mount a 20A jack on either side of the rear air vents under the center seat for a total of two. These will be accessible to the kids in the back.

I want to run a power cable from one of the batteries through the firewall to DC distro box that I will site under the front center seat. I'll come of that to the jacks.

1. There is a HUGE grommet just below and to the left (from the inside) of the steering column. It has a weird shape like a cable coming through into the engine compartment, but there is nothing running through it. Can anyone see a reason why I can't use that grommet, and do I need to leave the long rubber tube-like protrusion on it? Does anyone know what that grommet is meant for? It seems kind of big and purposely sited for just being there.

2. Can anyone see any reason not to install the AUX power plugs where I want them. they are 20A rated, but made of metal. Will this cause a melting/fire issue if mounted into the plastic air vent housing? Alternately, can someone point me to a place to buy plastic ones if it's an issue. I want to mount them into a hole, not bulkhead mounted.

3. I'm also installing a rear DVD system and need an ACC/Ignition run. Normally I would use an Add-A-circuit in the fuse box, but with the fuse box in the engine compartment, it seems to have complicated matters. Can someone recommend a place to tap into ACC near the center seat/console? I was thinking of coming off the power seat which is close by. It will be drawing about 1A.

Thanks for your help,

 

1. A picture of what you are talking about might be helpful. It does sound purpose-built from your description.

2. I don't see a reason why they would be an issue as long as you put an inline fuse rated at 20A max for the outlets. Just size your cable correctly for the current you plan on drawing. When you run your cable from the engine, don't hook it directly to the battery, use a fuse, or connect it after the main fuse in the fuse box. Otherwise, you will have an unprotected line directly to the battery, which IS unsafe if it were to short to any part of the frame/body. Batteries can put out hundreds of amps, plenty to cause a fire.

3. I don't know if I would come off of the power seats for your ACC. Instead, why not use the regular cigarette lighter in the front, since you will be running wires near it anyway, just run one more. The regular cigarette lighter shuts off when you remove the key (after you open the door), but the aux power outlets do not, at least in my truck. I'm not even sure that the power seats shut off when the key is not in the ignition.

 

Thanks for the reply.

Here's the pics:



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I was trying to avoid coming off of another cigarette lighter or power outlet as I use the current ones, and will also concurrently use the new ones. I know I will be plugging in an inverter on the new ones to run a playstation 2. Do you think it will matter?

I'm already looking at fusing the battery run, and the power outlets and DVD will also be appropriately fused at the DC distro box. I'll also be fusing the ACC run with a 20A.

does it matter if I come off the auxiliary battery, or should I stick to the cranking battery?

The power seats don't shut off..... just bumped the controls taking the pictures, and they work without the keys in the ignition.

Thanks for your help

 

It's hard to say what that is for. Maybe someone with more experience will chime in. I think I remember other people using the same hole as the speedo cable.

If you are going to run an inverter, why not just hook that up to the distribution box directly on its own fused output? Then you have a 110v outlet for anything you want. Most of the good inverters have terminals that you can run cables to instead of just plugging in to an accessory outlet.

As for the ACC trigger, I thought you were going to simply use that as a trigger for a relay that shuts off the power that you fed seperately when you leave your truck. That would be what I would do. That way you are not using much power off the current cigarette lighter, you are just using a small amount that triggers the relay and that relay in tern keeps the high current run on. You can also just connect directly to the constant feed, but you have to make sure that you don't leave anything on when you leave the truck or you will drain the battery.

 

Let's see what someone else thinks of that grommet..... It just seems awfully large to not be for something specific.... you could run a 400V mains line throught that thing! Obviously, it's not something that the truck needs as there is nothing there. I just wonder what's missing....

I only need the ACC run for the DVD system. However, I never thought of using a relay to shut off power when the key is off..... I'm thinking I may just do that.

In essence, If I'm understanding you correctly, I would be creating my own switched 12V circuit. I just pulled some wiring diagrams off of "the12Volt.com" for the use of relays, and it looks like that might just be the answer without even having to tap into a switched circuit.

Thanks for the tip!

As for the inverter, I thought about that, but I don't use it enough in the truck. Just that odd trip when the kids want more than DVD's or handheld games. I thought of just plugging it in up front where I normally do, but I bought a GPS with traffic service that just took that plug, and the other two are being used by the ipod and phone charger most of the time.

I'll be diving into it this weekend, I'll post results.

Thanks again

 

Your truck is standard right?? My truck is Auto and has a cable run through this grommet. I believe it could be the brake release for the transmission. (Apply Brake to move Shifter).

 

Yes, my truck is a standard. I guess that would answer that question. Well, I have to say.... it's pretty convenient for running cables! thanks for bringing that to light, RamSportBlue.

I've purchased the RAM Shop Service manual on CD, and I couldn't find anything in there about it.