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Topic: Fridge 12 volt disconnect (Read 1146 times) previous topic - next topic

Fridge 12 volt disconnect

1998 U-320

The other day I went to work on the LP fridge.  I shut off the 30 amp shore power breaker, and turned off the 12 volt coach battery switch at the stair well.

I put a volt meter across the power terminal screws at the back of the fridge and found it hot with full battery voltage.

Are the LP fridges essentially hard wired to the coach batteries?

When I look at drawing B-2126 it appears that the fridge is on wire run B28.  To me it looks like this connects to 90 amp breaker, but by-passes the manual battery switch that comes in on run B17.  B28 also powers the LP detector and the dash memory.

So does this mean you need to remove a battery cable to remove 12 volt power to the fridge?

Thanks,
Chris


Re: Fridge 12 volt disconnect

Reply #1 –
Should be fused or on a breaker somewhere. Helps prevent your wires from running out of smoke.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Fridge 12 volt disconnect

Reply #2 –
Refer is wired to the house batteries direct.  I assume a fuse somewhere.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Fridge 12 volt disconnect

Reply #3 –
Thank you both.

Yes, it's on a 30 amp resettable breaker in the pass through storage bay.  But I'm not seeing a switch to shut the power off to the fridge for times someone may want to work on it.

Caflashbob - your post came in when I was responding.

Chris

Re: Fridge 12 volt disconnect

Reply #4 –
No shutoff.  On purpose.  Disconnect house battery cable.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Fridge 12 volt disconnect

Reply #5 –
Using a meter and wiring diagram, identify the few breakers on the bay wall behind a white fiberglass covering that are not on the stairwell switch.  Others are detectors.  Just unscrew the wire at the breaker, much cleaner then removing battery cable clamp which can be weaken by retightening.

Re: Fridge 12 volt disconnect

Reply #6 –
If you look  to the left of the plastic box that covers the control board at the back of the refrigerator, you will see a small panel with a red wire (positive) and below it a black wire (ground). This is the 12V disconnect for the fridge. Disconnect either one.
1994 U280, Build 4490
Deming, NM.

Re: Fridge 12 volt disconnect

Reply #7 –
Barry - I looked at that option.  The wires there have ring terminal ends that attach to the breaker posts.  There is not a clean way to cover the end of the loose wire to ensure it doesn't come into contact with another post or bus strip.

Twig - This is the option that I took. 

I disconnected the +12 volt wire from the coach battery side of the terminal strip at the fridge, and put a wirenut on the end so it doesn't come in contact with anything.  I did not have room to remove the +12 volt wire from the fridge side of the strip without running the risk of grounding that wire to nearby objects. 

Still not my favorite option for disconnecting power, but at least disconnecting at this point is downstream from the fridge's 30 amp manual resettable breaker.  There is a little more protection than using a wrench in tight quarters where the coach batteries are located and dealing with all 600+ amps.

Now why am I asking...

A previous owner had some work done on the fridge adding a component that I have no idea what it is (posted about it a while back), and a couple years ago they added a new cooling unit.  The tech who did one of these jobs added some length to a positive wire coming off the control board by using spade connectors to make the splice.  BUT... they left the female spade connector uncovered without an insulating jacket.

I didn't know of the condition.  The other day I was checking something back there with the fridge running and this uninsulated connector made contact with a bare metal plate and blew the 3 AMP AGC fuse on the control board.  Took me a while to trace down what happened.

The exposed female spade connector end is now redone and properly jacketed.  Fuse is replaced.  Fridge is running again and being tested.

Chris

Re: Fridge 12 volt disconnect

Reply #8 –
Mike,

I think they are talking about 12 VDC to the refrigerator PC board, not the 120 VAC for the heat element.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Fridge 12 volt disconnect

Reply #9 –
Chris, electrical tape around the open connection & a few wire ties to keep cable from flopping around could work.
 

Re: Fridge 12 volt disconnect

Reply #10 –
Barry,

Thank you for your post.

I crimped on a new jacketted/insulated female spade connector, and rerouted the wire to a better location.

Chris