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Author Topic: 12v system not working/ need advice please.  (Read 384 times)

12v system not working/ need advice please.
« on: November 03, 2019, 01:28:13 PM »
Hey, my name is Joey. I live in a 2009 Keystone cougar and have been for a few years now. Recently my 12v system started bugging out on me. No lights, water heater, or fridge atm. But if I use the microwave which is AC then the fridge comes on and interior lights. I'm new to these issues and have tried to research it online but cant find anything with this exact situation going on. I'd be very greatful for any advice or suggestions. Thanks in advance.

Rene T

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Re: 12v system not working/ need advice please.
« Reply #1 on: November 03, 2019, 03:26:13 PM »
I have no idea but I just wanted to welcome you to the forum. Others will be along soon with questions for you.
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John From Detroit

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Re: 12v system not working/ need advice please.
« Reply #2 on: November 03, 2019, 04:13:21 PM »
The Microwave should NOT have anything to do with the 12 volt systems but.. It might if you are on 50 amps and not using A/C or selected other things.

YOu need a volt meter and meter not the 12 volt system (To start we do that later) but the 120 volt system at teh breaker panel

For a 50 amp RV you should see 120 volts between the two black wires (or black and red) connected to the 50 amp breakers and the WHITE bus.> Caution dangerous voltage/current DO NOT TOUCH ANY METAL in the box when measuring.. Also each breaker down the line should show 120 volts to the white bus. any burned or loose connections need fixing (Suspect #1  Screw loose).  YOu should also see 240 volts (if plugged into 50 amps) between the two 50 amp main breakers  if you are on a 30 amp site with adapter you won't see that (zero side to side).

IF you are in a 30 amp rig.. None of the above applies.   Save the screw loose

To check for screws loose UNPLUG and apply screwdriver.. If they are loose (Check 'em all) tighten and then once done plug back in.

Next we get to the 12 volt side of life but I'll leave that for tomorrow.
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Back2PA

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Re: 12v system not working/ need advice please.
« Reply #3 on: November 03, 2019, 04:47:19 PM »
So just to confirm:


1) you always have 120V (microwave always works)?
2) As John from Detroit asks, is this a 30 or 50 amp trailer?
3) Are you plugged in to 30 or 50 amp shore power?
4) You have no 12v power except when running the microwave?
5) As soon as the microwave stops the lights go out?
6) Do you have a voltmeter plugged in to one of your AC receptacles? If you don't have one it would be good to get one, they're cheap
7) will your power cord reach to another site?



Scott
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cerd

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Re: 12v system not working/ need advice please.
« Reply #4 on: November 04, 2019, 05:17:01 AM »
I would suspect a loose connection for the 12v converter in the power distribution box. I wonder if the microwave is causing the wire for the 12v converter to somehow arc, making a temporary connection before it becomes loose again.
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Back2PA

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Re: 12v system not working/ need advice please.
« Reply #5 on: November 04, 2019, 05:41:11 AM »
I would suspect a loose connection for the 12v converter in the power distribution box. I wonder if the microwave is causing the wire for the 12v converter to somehow arc, making a temporary connection before it becomes loose again.


I was thinking either that or (if it's a 50A rig) a problem with the neutral where the load from the microwave is somehow affecting the balance between L1 & L2. That's why I suggested trying another shore pedestal to try and ascertain whether the problem is within the rig
Scott
2014 Montana High Country 343RL (37')
2011 SD F-250 Crewcab LB 4x4, 6.2 Gas, 10K gross
Eezrv TPMS
Fulltimer

xrated

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Re: 12v system not working/ need advice please.
« Reply #6 on: November 04, 2019, 05:44:20 AM »
I would suspect a loose connection for the 12v converter in the power distribution box. I wonder if the microwave is causing the wire for the 12v converter to somehow arc, making a temporary connection before it becomes loose again.

That..^^^^^...is a very good guess, and something that has a very real possibility....and should be checked out!
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Re: 12v system not working/ need advice please.
« Reply #7 on: November 04, 2019, 11:27:44 AM »
Hey guys. Ok I forgot to mention it is a 30 amp service in the camper not 50. I will check for a loose connection at the breaker panel. I've been without a battery for a couple years now and everything has worked fine until recently. So yesterday I connected a battery to see if that solved any issues and it didn't, so I walked back outside with a plastic item to tap on the 12v circuit breaker next to the battery box, I went back in and 12v lights and fridge were working. Then I disconnected the battery and everything went off again. I'm assuming the 12v circuit breaker is bad for one. But the microwave deal has got me worried now.

Richard R

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Re: 12v system not working/ need advice please.
« Reply #8 on: November 10, 2019, 04:21:25 PM »
I had this happen on my new Connect trailer.  We were on the road on a long trip.  I called my RV dealer and he walked me through it.  It turned out to be a blown relay that was mounted on the tongue frame.  I replaced it (very cheap) and all worked well.  If you find that breaker, its directly from the battery before it enters the trailer.  You can test it by jumping across the terminals to see if everything works.  Any RV dealer can sell you a replacement.