7 Pin Trailer Wiring Aux Power

[Andyb_aus]

Hi, I have a 2011 3L CRD Grand cherokee Australian delivery. Can the trailer reversing light output be reprogramed to provide 12 volt Ignition on power. My caravan has this pin wired to run a fridge while driving. The 7 Pin wiring diagrame show pin 2 as reversing / Aux power

Cheers Andy

[Mace1]

Short answer, yes it can, you would have to run a cable from either the battery or a nearby power socket into this terminal on your vehicle 7 pin socket. If from the battery, it will need to be fused.

However, pretty inefficient due to the long distance back to the fridge. Max current deliverable would be in the order of 5 amps.

Better to run a dedicated power supply direct from the battery via heavy duty wiring, connected by Anderson Plugs back into the caravan electrical system.

My opinion only...

[5oclock]

Most 3way caravan fridges pull between 10 to 15amps on 12volt, so Mace is spoton. However the newer compressor fridges are around 4amps, but they dont like the voltage drop on the surge when the compressor fires up. So either way its much better running a nice heavy wire.

[JoergM]

Originally Posted by Mace1

Short answer, yes it can, you would have to run a cable from either the battery or a nearby power socket into this terminal on your vehicle 7 pin socket. If from the battery, it will need to be fused.

However, pretty inefficient due to the long distance back to the fridge. Max current deliverable would be in the order of 5 amps.

Better to run a dedicated power supply direct from the battery via heavy duty wiring, connected by Anderson Plugs back into the caravan electrical system.

My opinion only...

I just wrote on a different post that I did exactly that. And it fried my heavy duty cable although I had a fuse installed. It literally melded off the copper. The additional stress of the dual Battery which sit before the fridge in my trailer and the heat was just too much. So I would rather install a sep. battery or two on the trailer and charge it with a good solar panel (160 to 200W). That's what I did and should have done from the beginning. Had never any issue again after that installation.

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[5oclock]

Cricky that looks nasty JoergM, glad you didnt have a fire.
It can be a bit tricky getting your fuse amp rating and cable size worked out. Better to be a bit on the light side with the fuse and work upwards if you have to. Also worth testing the finished set up with a "controlled over load" so you can rest easy that the fuse/circuit breaker will do its job.

[Mace1]

Originally Posted by JoergM

I just wrote on a different post that I did exactly that. And it fried my heavy duty cable although I had a fuse installed. It literally melded off the copper. The additional stress of the dual Battery which sit before the fridge in my trailer and the heat was just too much. So I would rather install a sep. battery or two on the trailer and charge it with a good solar panel (160 to 200W). That's what I did and should have done from the beginning. Had never any issue again after that installation.

Wow. that looks nasty...

My only comment would be that the HD wiring to an Anderson plug should allways be of appropriate size and fuse size, and be installed away from any other wiring. Mine runs directly from a redarc isolator underneath the vehicle and is attached to various mounting points beneath the vehicle..

[JoergM]

Originally Posted by Mace1

Wow. that looks nasty...

My only comment would be that the HD wiring to an Anderson plug should allways be of appropriate size and fuse size, and be installed away from any other wiring. Mine runs directly from a redarc isolator underneath the vehicle and is attached to various mounting points beneath the vehicle..

It was even scarier when in the car . To be honest, this was something I came up last minute when I got the trailer and cobbled it together. We left Melbourne, moving to Queensland. I just thought I could use the existing wiring for the dual battery and re-route a Anderson plug. I disconnected the battery and had only the Anderson Key on it, still it was too much for it. I had my worries that something like this would happen and I wanted to check it but with all the other stuff going on, I completely forgot about it till we had smoke in the car.

The wire was certainly thing enough for the load. It was just the heat together with the outside heat (45+). And the engine was also getting hotter, with the A/C on. Well it is ok now, since it is not connected to the car electricity at all anymore.