Rewire 12v Outlets to Aux Battery - Dodge Caravan

[The Travelling Pear]

Hello,

I've recently added an auxiliary battery to my "camperised" 2006 Dodge Caravan. My next step is to add loads to the battery.

I would like to re-wire the 2 12v outlets and the internal lights to run off the auxiliary battery. Does anyone have any ideas of how to do this? For the outlets, my rough idea is to remove the panelling around the outlets and try to trace where the wires go, then cut the wire and splice over to the aux battery. The lights are a bit more difficult, if I still want them to be controlled by the switch in the dash.

Does anyone know if there's a guide to where to intercept wires and which colors correspond to which circuits? I've found the "Wiring" section of the Repair Manual, but haven't had any luck.

Thanks,
Andrew

 

[tx2sturgis]

It's a WHOLE lot easier to add new power ports. Just wire them to your auxiliary battery.

 

[highdesertranger]

Texas is right. much easier to do it that way. highdesertranger

 

[XERTYX]

What exactly is that doohickey on the side of the starting battery? My preferred van is a 2005 or newer dodge caravan with stow and go seats. Or better still a retired mail carrier dodge caravan I could KICK myself for not buying when I had a chance. It had no side windows and a wire cage walk thru man door rear access.

They're right. Just put in some 12v ciggy lighter ports and that gives you 2 more ports. The 2 from the vehicle system and the 2 from your aux battery. For lights just run some LED lights back to the aux and a switch up front if you want them switchable from the cab.

 

[tx2sturgis]

And in some vehicles the dome lights are actually controlled by the ECM, BCM, or PCM and have features like auto-dimming and delay. Rewiring those to work thru the door switches and powered from the auxiliary battery might be a nightmare.

I have no idea if this vehicle has those kind of courtesy lights.

I would just add 12v LEDs such as dimmable RV interior lights or LED strip lights. Either will work well and won't compromise the factory wiring.

 

[The Travelling Pear]

And in some vehicles the dome lights are actually controlled by the ECM, BCM, or PCM and have features like auto-dimming and delay. Rewiring those to work thru the door switches and powered from the auxiliary battery might be a nightmare.

I have no idea if this vehicle has those kind of courtesy lights.

I would just add 12v LEDs such as dimmable RV interior lights or LED strip lights. Either will work well and won't compromise the factory wiring.

You're right - the interior lights auto power off a minute after locking the car. They're also partly controlled by a dimmer switch on the dash. My concern with LEDs or other lights is that I'd need to cut into the headliner and figure out how to route wires behind it. That sounds difficult... 

What exactly is that doohickey on the side of the starting battery? My preferred van is a 2005 or newer dodge caravan with stow and go seats. Or better still a retired mail carrier dodge caravan I could KICK myself for not buying when I had a chance. It had no side windows and a wire cage walk thru man door rear access. 

They're right. Just put in some 12v ciggy lighter ports and that gives you 2 more ports. The 2 from the vehicle system and the 2 from your aux battery. For lights just run some LED lights back to the aux and a switch up front if you want them switchable from the cab.

It's a smart battery isolator. It allows the auxiliary battery to charge from the alternator while the vehicle is running, but disconnects while the vehicle is off, so that the starter battery doesn't get drained.

Thanks for the feedback about installing a new 12v outlet.

 

[B and C]

The plastic trim moulding comes out pretty easy to run wire behind.  You could then poke a hole in the headliner near the trip and mount the light there.

I have installed a few of these cheap 12V outlets (surface mount) for light loads like charging a phone or laptop: https://www.ebay.com/itm/254022371628

 

[tx2sturgis]

My concern with LEDs or other lights is that I'd need to cut into the headliner and figure out how to route wires behind it. That sounds difficult... 

Trust me, routing small wires thru the trim and mounting small light fixtures will probably be a cake-walk compared to messing with the factory wiring harness.

Often times the plastic trim just snaps off, or can be peeled back just enough to route your wiring. A small plastic hook shaped upholstery tool can be bought at places like AutoZone or online to help you with it.

Be sure to properly fuse all your wires close to the battery. And if your wires pass close to or touch metal surfaces, be sure to protect them with split-loom, tape, heat shrink, or similar.

 

[The Travelling Pear]

Trust me, routing small wires thru the trim and mounting small light fixtures will probably be a cake-walk compared to messing with the factory wiring harness.

Often times the plastic trim just snaps off, or can be peeled back just enough to route your wiring. A small plastic hook shaped upholstery tool can be bought at places like AutoZone or online to help you with it.

Be sure to properly fuse all your wires close to the battery. And if your wires pass close to or touch metal surfaces, be sure to protect them with split-loom, tape, heat shrink, or similar.

Thanks for the advice. I went ahead over the weekend and installed 4 new outlets (all connected to the auxiliary battery):
- drilled holes in back right panel for 2x 12v cigarette lighter outlets
- replaced the rear right cigarette lighter outlet with a usb outlet
- replaced the front console cigarette lighter outlet with a usb and voltmeter combo outlet

So far, I'm grounding most of the outlets on nearby chassis screws. Is this okay (rather than having a return ground wire to the battery)?

 

[B and C]

This is fine as long as your house battery is also grounded.

 

[highdesertranger]

make sure you sand/grind the paint off to make a good connection. then you can attach the wires and repaint to keep from rusting.

Ancor wire, nice. can't beat quality.

highdesertranger