Thread Tools Display Modes
Old 05-26-2015, 01:07 PM   #1
Junior Member
Join Date: May 2015
Posts: 2
lights/fan not working on 12V

I recently inherited a 2005 Forest River Flagstaff popup trailer. It did not have any manual and I haven't had a 'walk through' from a dealer..yet. I went around the trailer and with the help of a neighbor who is an RV enthusiast was able to figure pretty much everything out.

However, I am having issues with the interior lights and ventilation fan not working off the battery power. When the trailer is plugged in to shore power the interior 12v stuff works, lights/fan run fine (from reading the forums this suggests the switch under the range is working fine, or the lights wouldn't work under shore power either). However when the trailer is not plugged in to shore power (and battery is verified 100% charged) the interior lights and ventilation fan will not operate.

I checked the fuses in the breaker box and flipped the breaker switches on and off. I know the lights and fan work because they run when shore power is connected. Any suggestions as to why they won't run when no shore power is connected and the battery is in working order? Btw, the battery works the electric motor that raises and lowers the camper just fine.

Any direction is greatly appreciated!


doval is offline   Reply With Quote
Old 05-26-2015, 01:26 PM   #2
Phat Phrog Stunt Team
TURBS's Avatar
Join Date: Aug 2011
Location: Iowa
Posts: 34,205
Be looking for a Resetable circuit breaker under the A-frame tongue.
Follow the positive battery cable to it possibly.

08 duramax tuned n modded, 32bhok Sabre
2015 camping "9 nights"

TURBS is offline   Reply With Quote
Old 05-26-2015, 01:53 PM   #3
Junior Member
Join Date: May 2015
Posts: 2

I had the trailer plugged in to shore power to keep the battery charged and to let the fan run to air out the trailer after being packed up all winter. I went out to look for a circuit breaker on the outside as you suggested, and just to be safe unplugged the shore power first. I checked the battery and looked for a circuit breaker but all I found was the in-line fuses on the pos+ battery connections. I then noticed that the fan was working, and hadn't shut off when I unhooked the shore power. I tried the lights and they work fine. I don't know what I did but it's now working.

While my symptoms are resolved I'm curious to know what might cause this scenario? If it continues to occur I'll post more..

Thanks for your help!
doval is offline   Reply With Quote
Old 05-26-2015, 02:37 PM   #4
Senior Member
Join Date: Aug 2014
Location: West Jordan, UT
Posts: 646
It seems to me that maybe the battery was not charged. How did you verify the battery was charged (not trying to insult your intelligence)? Or it could be a weak ground?
2015 Forest River EVO 2850
2012 Dodge Ram 2500 6.7 Cummins
Yamaha 2k x 2 with parallel cable
EMS 30 PI portable w/ Edison plug

Nights Camped (2016-13) (2015-13)
SuicideSaints is offline   Reply With Quote
Old 05-26-2015, 05:38 PM   #5
Senior Member
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 519
It may be a corroded connection on one of the wires. By moving wires around a bit when you were checking the in-line fuse you may have made connection again.
Check all your wiring for corrosion in and around the battery box.

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting - Boon Docking 99% of the time.
2009 F150 - 5.4 Litre - 6 speed - Tow Package
boondocking is offline   Reply With Quote

fan, light

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 07:45 AM.