Thread Tools Display Modes
Old 05-19-2015, 08:08 AM   #1
Senior Member
dkb74's Avatar
Join Date: Feb 2013
Location: Tampa, FL
Posts: 543
Where does the power draw from (cig lighter vs. outlet)?

I am curious if anyone knows where the power is drawn from for the cigarette lighter socket and the outlets in different scenarios?

For instance:
1. When the engine is running, but the generator is not on.
2. When the engine is running and the generator is on.
3. When we are parked and connected to a power source.

I don't want to drain the battery if the cig lighter sockets only draw from the battery when the engine is turned off.

The reason I ask is because we have phone chargers and satellite radio connectors that can use either/or. I'm wondering if we need to have both while traveling.


~ Darlene ~

2014 Coachmen Mirada 35BH

previous owner of
2014 Rockwood Mini-Lite 2306
dkb74 is offline   Reply With Quote
Old 05-19-2015, 07:55 PM   #2
7 Year Class A RV'er
Join Date: Oct 2014
Location: Winter Park, FL
Posts: 875
The lighter is getting 12v from the battery. I doubt you'd ever drain the battery charging a phone but guess it could be possible. The outlets should not have power unless 1) you have an inverter that converts 12v from the battery to 110v at the outlet, or 2) the generator is running or 3) you are on shore power. Hope that answers your question.

2015 Legacy SR340 360RB
2014 Jeep Wrangler Unlimited Toad

Gigi, Poppy and Sadie Lady...On the road, but not full time!
conceptumator is offline   Reply With Quote
Old 05-19-2015, 08:59 PM   #3
Senior Member
Join Date: Jun 2013
Posts: 182
Without knowing your type of coach the best answer I can give you is this:

12v Aux port built into factory cab dash = draws power from chassis battery (engine battery)

12v Aux port in coach area (everywhere but the cab) = draws power from coach battery

Now to maybe answer your second question... Most newer and older higher end coaches have a system called BIRD that connects both the chassis and coach batteries together if a voltage of 13.x+ is detected at either battery source.

What does that mean? If your engine is running your chassis battery is being charged/maintained as you'd expect plus a charge current is also being sent to the coach battery. If your coach has 120 volts AC (generator or power pole) then your coach batteries are being charged as you'd expect plus current is also being sent to your chassis battery.
2011 Sunseeker 3170DS - 30,000 miles explored
funfinder5 is offline   Reply With Quote
Old 05-20-2015, 06:53 PM   #4
Senior Member
ernest917's Avatar
Join Date: Jun 2011
Location: Woodville, Texas
Posts: 1,387
This I can answer due to having two of mine recently worked on.... The outlet by the leveler keypad and one on the dash draw power from house batteries and here's a 20 amp fuse in lower fuse bank that control them.... The other 12V outlet on dash draws power from engine WHEN KEY IS ON...... Makes it perfect for plugging in my sat radio.... I plug in a 12V splitter into the outlet by the leveler keypad and plug in my GPS and TPMS..... FYI: I kept blowing that 20amp fuse and we finally discovered that the wires plugged into the plug itself were loose and it wouldn't ground....

Sent from my iPad using Forest River Forums
ernest917 is online now   Reply With Quote
Old 05-20-2015, 06:54 PM   #5
Senior Member
ernest917's Avatar
Join Date: Jun 2011
Location: Woodville, Texas
Posts: 1,387
Also FYI - I have a Berkshire

Sent from my iPad using Forest River Forums
ernest917 is online now   Reply With Quote
Old 05-23-2015, 12:05 PM   #6
Senior Member
Join Date: May 2012
Posts: 357
My 2011 Georgetown 327DS has only the cigarette outlet on the dash readily accessible. That draws from the chassis battery and is powered all of the time, even with no key in the ignition. There's another similar outlet in the overhead cabinet above the passenger seat, behind the antenna switchbox where it's almost impossible to reach and use.

I needed additional 12V circuits so I installed a (fused) direct line from the battery to the drop leaf table cabinet behind the passenger seat. It has two PowerPole outlets and is capable of supplying 30A if necessary. After I replaced all of the interior lights with LEDs, I added another 12V outlet under the front facing bench seat at the dining table. That 12V circuit is powered by a tap off of the lighting circuit for the street side slide which runs through that bench seat. The bench seat circuit also powers a 50W inverter that provides enough power for a litterbox, sewing machine, or soldering iron.

pmsherman is offline   Reply With Quote
Old 06-08-2015, 10:14 AM   #7
Senior Member
waiter21's Avatar
Join Date: Jun 2015
Posts: 431
12 volt Cigarette plugs

The dash cigarette lighter plug is probably wired to the chassis battery and may only be active if the engine is in ACC or running.

The cigarette plug on the antenna amplifier (if you have one) runs off the coach battery.

When the engine is running, both batteries should be tied together so the engine is charging both batteries.

120 volt outlets

Unless you have an inverter, your outlets will only be live (have power on them) when your plugged into shore power or your generator is running.

Here is a simple electrical diagram that may apply to your Mirada.

Attached Thumbnails
Click image for larger version

Name:	BasicMH_Electrical.jpg
Views:	73
Size:	69.4 KB
ID:	79413  

2001 Coachmen Mirada (Ford F53 6.8L V10) - Toad 2001 Civic
It won't do MACH 2, but I can get a sandwich and take a pee.
waiter21 is offline   Reply With Quote

light, power, electrical

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Virginia Campgrounds

Reviews provided by is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 09:31 PM.