Electrical Burnt another 12 pin plug

Macca_75

Well-Known Member
Aug 3, 2016
510
452
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SE Suburbs, Vic.
#1
So the fridge stopped working on 12v connected to car again this weekend. Checked the plug and sure enough I have melted to middle of the top row of pins (which is what the fridge connects to).

2nd time round so 1) I have been careful to ensure the pins are fine when connecting the plug and 2) This won't happen again.

What have others done? How is your fridge wired to run when connected to the car and travelling.
 

millers

Active Member
Mar 25, 2011
213
159
43
Adelaide
#2
I would suggest that changing to Anderson is required for more current carrying capability and better connection.

Heat generated at the connector means that the cable to connector (both sides) and / or connector to connector resistance is too high generating heat that can not disipate quick enough.

Most mechanical connections (screw type) have issues with contact surface area and the connector to connector oxidises over time increasing the resistance and therefore the heat.

Caravaning been on the back burn for a while, but I have been looking at the 7 pin flat combined with 50 Amp Anderson and make the caravan cable so that I plug in as a single action.
 

Macca_75

Well-Known Member
Aug 3, 2016
510
452
63
44
SE Suburbs, Vic.
#3
I already use an Anderson to charge the battery(ies) while travelling. Could I run both the Fridge (DC) and charge the batteries on the same Anderson or would it require another separate cable?
 

Drover

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Nov 7, 2013
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#4
You will probably find the weight and movement of the cable is pulling the socket terminals, as for drawing power for the fridge from your Anderson it shouldn't be a problem really just use the wiring from your 12 pin, van side, and tap it into the Anderson, if your Anderson pins are soldered then dismantle them , join up your fridge wires and resolder the pins, if crimped you could just piggy back solder them but I would just cut and replace the pins with new ones soldered in....the Anderson is rated more than enough to handle the current and the tug side for fridge and 12v should be on the same circuit...Does seem strange to have battery charge on an Anderson and fridge on 12 pin, go over and check the circuits, before you mod them...
 

Macca_75

Well-Known Member
Aug 3, 2016
510
452
63
44
SE Suburbs, Vic.
#5
The Anderson definitely recharges the battery. My only *concern* is if I wire the fridge to the Anderson, 12v will always be available to the fridge (regardless if the car is connected or not). So if the fridge were ever changed from Auto to DC, I would flatten by battery very quickly.....

May need to see if I can fit a relay off something to detect the car and run the fridge via this
 

Boots in Action

Well-Known Member
Mar 13, 2017
779
712
93
Ferny Grove, Queensland
#6
The Anderson definitely recharges the battery. My only *concern* is if I wire the fridge to the Anderson, 12v will always be available to the fridge (regardless if the car is connected or not). So if the fridge were ever changed from Auto to DC, I would flatten by battery very quickly.....

May need to see if I can fit a relay off something to detect the car and run the fridge via this
Hi @Macca_75 , I got rid of my old 7 pin plug and refitted a 12 pin plug. The top 5 pins in the 12 pin plug are rated at 35A and the bottom 7 are only rated at 15A. I have a dedicated pair of 8 B&S cables running to van fridge and connected to tug with Anderson plug. I also have a dedicated 8 B&S single cable running to Setec to charge van battery. I use one of the heavy duty 35A pins in the 12 pin connector for that and another of the 35A pins as a heavy earth return between van and tug. The bottom 7 pins (15A) are only used for tail/stop lights, running lights, turn indicators, van electric brakes and a lighter separate earth return to tug for these loads. Both the fridge wires and the wire for charging the van battery from tug operate through a Voltage sensitive relay and a 100A circuit breaker. The VSR will prevent any discharge power to fridge once tug battery voltage drops below 12.6 volts. It also isolates the van battery even though the charge line to van battery incorporates a power diode in series (in Setec) which prevents current bleeding back to tug battery. When connected to tug and engine running, relay connects the fridge/ van battery to tug alternator/battery power when voltage gets to 13.4 or above. No chance of getting a flat tug battery and no switches to remember to turn on/off. All automatically done!! Also no load on tug battery on starting as no connection made until voltage gets to 13.4 volts. Hope this gives you some ideas on how to upgrade.
 

Bluey

Well-Known Member
Mar 31, 2014
3,301
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victoria
#7
Nearly 5 years with 12 pin plug no issues i feel it often when traveling and never feels hot ..... touch wood
 

Drover

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Nov 7, 2013
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#9
@Macca_75 what stops your fridge flattening your battery now ????????? swap it over to the charging/anderson circuit on your tug then...............

I ran my 12pin for donkeys on the Jeeps no drama but on The Ute the plug was mounted the other way with the HD pins on top, the cable pulled down a fraction and the HD pins moved a mm or so and burnt out, changed to 7 pin and ran the fridge power circuit via an Anderson, no 12v charging circuit on my rig as the solar does it all, my van cam draws its power from the frdige circuit then if cam drops off I know the fridge has stopped, has happened sometimes, just dirty contacts.
7 pin is way cheaper than a 12 pin anyway and with an anderson you can better sized cable.
 

Macca_75

Well-Known Member
Aug 3, 2016
510
452
63
44
SE Suburbs, Vic.
#10
@Macca_75 what stops your fridge flattening your battery now ????????? swap it over to the charging/anderson circuit on your tug then...............

I ran my 12pin for donkeys on the Jeeps no drama but on The Ute the plug was mounted the other way with the HD pins on top, the cable pulled down a fraction and the HD pins moved a mm or so and burnt out, changed to 7 pin and ran the fridge power circuit via an Anderson, no 12v charging circuit on my rig as the solar does it all, my van cam draws its power from the frdige circuit then if cam drops off I know the fridge has stopped, has happened sometimes, just dirty contacts.
7 pin is way cheaper than a 12 pin anyway and with an anderson you can better sized cable.
At the moment my fridge runs directly from the car, not the van battery. This is the 2nd plug on the van I will have to replace. Might have to get an Autoelec to give the car a once over.
 

Drover

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Nov 7, 2013
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#11
No, I didn't mean van battery @Macca_75 I meant the car battery, if it your fridge doesn't flatten your car battery while it was wired in the 12 pin then that means you have something fitted somewhere ??? either in car or van that acts as a fridge switch, therefore remove the wires from the 12 pin on car side and fit an Anderson plug, Do the same on the 12 pin on van and bingo no dramas it will all work as before just no meltdown......if your 12pin will still connect up it will be okay for all the other wires as they don't draw as much.....

Otherwise just replace.........If the HD pins are on the upper level of your socket it will happen again just change to Anderson and save future hassle.........I've been there....,.......you don't want to run your fridge off the van battery, ever.
 
Last edited:

barney120

Active Member
Dec 10, 2013
156
151
43
51
Kangaroo Valley
#12
Yep, I towed for years with just 12 pin trouble free then pulled up at Hill End and plugs melted together. Next stop was to get dedicated anderson plug fitted to tug and van for fridge only. Never have to worry again.
 
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jazzeddie1234

Active Member
May 19, 2016
101
99
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Mandurah
#13
I carry a small (well tiny really) flat blade screwdriver and regularly check the gap in the pins. Use the blade to gently open the gap to get a better contact - being careful not to short anything. The socket also gets quite dirty so it gets a regular flush with plenty of WD40.
 

Roadhouse

New Member
Mar 12, 2019
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0
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Lake Macquarie
#14
you don't want to run your fridge off the van battery, ever.
Hey Drover - can you enlighten me on this plz as I am new to this van caper...

About to pick up a van which has a 12 pin plug with no wires in pins 8-12 but has one Anderson plug which the seller thought ran the fridge on the move. I think it must charge van battery instead as van has TS2000 breakaway system which is powered by van battery only, so van battery must surely be being charged on the move so breakaway can operate if required.

If I am right, and Anderson is to charge van battery, I presume fridge runs off the battery. You said never do this - what is the issue?

Cheers
 

jazzeddie1234

Active Member
May 19, 2016
101
99
28
Mandurah
#15
The breakaway has it's own battery and charger system. Mine is under the bed and has a test button to check, or you can pull the breakaway plug out to see if you can move forward - that's what the cops do.
I would guess the anderson powers the fridge. On my jayco the van battery is trickle charged via one of the 7 pins.
The fridge draws lots of current so will flatten a van battery pretty quick so the usual way is for a direct connection (via a relay) to the tow vehicle alternator
 

Roadhouse

New Member
Mar 12, 2019
6
0
1
Lake Macquarie
#16
The breakaway has it's own battery and charger system. Mine is under the bed and has a test button to check, or you can pull the breakaway plug out to see if you can move forward - that's what the cops do.
I would guess the anderson powers the fridge. On my jayco the van battery is trickle charged via one of the 7 pins.
The fridge draws lots of current so will flatten a van battery pretty quick so the usual way is for a direct connection (via a relay) to the tow vehicle alternator
Thanks for the reply.

The ts2000 breakaway doesn’t have its own battery. Previous models did but the 2000 uses the main van battery.

But you could be right though - the van battery may get trickle charge from tug somehow and Anderson runs fridge on the move. I guess I won’t know until a get there and do some testing to see what’s connected to what.
 

Drover

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Nov 7, 2013
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#17
Hey Drover - can you enlighten me on this plz as I am new to this van caper...

About to pick up a van which has a 12 pin plug with no wires in pins 8-12 but has one Anderson plug which the seller thought ran the fridge on the move. I think it must charge van battery instead as van has TS2000 breakaway system which is powered by van battery only, so van battery must surely be being charged on the move so breakaway can operate if required.

If I am right, and Anderson is to charge van battery, I presume fridge runs off the battery. You said never do this - what is the issue?

Cheers
A 3 way fridge would suck the life out of a battery in an hour or so unless its connected to a continuous charge supply, the anderson will more than likely be to run your fridge whilst traveling, it should have a relay/fridge switch unit somewhere in the line so when you stop your engine it will shut the power down otherwise you go shopping and come back your engine won't start as your battery s flat, if you have a multi meter or just a simple test light you can check...... The 12 pins can burn out if the pins are loose or dependng on how its mounted they can pull out slightly and the resistance will cause heat & the pins melt the case......

The van battery is there to run everything else in your van just not the fridge, BUT if you have a compressor fridge it will run off the van battery, usually have at least 2 batteries of 120ah or more with heaps of solar on the roof, they are just like a huge Engel.

The fridge running on 12v will keep it at temp but its only for driving, gas or 240 for camping use, if you have a look on here there are a number of threads which go into the fridges quite well.
 

Roadhouse

New Member
Mar 12, 2019
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Lake Macquarie
#18
Cheers mate - good info. Been trawling the boards trying to suck in as much info as possible in as short a time as possible. Plenty of reading ahead!

Just don’t really know the set up the new van has as seller can’t provide much info unfortunately. All will be revealed in a few days when I lay my eyes on it.

My issue was ensuring breakaway is operational as it runs off van battery but I think I will be ok the more I think about it. I will have a battery monitor so that will keep me informed regardless.
 

Drover

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Nov 7, 2013
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#19
If the instructions for the breakaway isn't there download one from online, they should draw power for charging from the tug but I think a lot draw from van nowadays, with solar keeping the van battery charged they stay charged up, they have purple and orange wires amongst others so are easy to find....something to discover when you get it for sure.
 
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Roadhouse

New Member
Mar 12, 2019
6
0
1
Lake Macquarie
#20
If the instructions for the breakaway isn't there download one from online, they should draw power for charging from the tug but I think a lot draw from van nowadays, with solar keeping the van battery charged they stay charged up, they have purple and orange wires amongst others so are easy to find....something to discover when you get it for sure.
Yeah def from van batt. Should be fine - batt monitor will give me peace of mind too.