Yes, if you drive enough.

I blow that fuse in my truck frequently. But then I'm towing all kinds of trailers almost daily. I think my dump trailer sucks too much juice when I have to dump a really heavy load.

I had a fuse in my truck that was a chronic problem. From NAPA I purchased an auto reset circuit breaker, that has a fuse base and fits into the fuse box. No more replacing the fuse every trip. They are available in standard amperage ratings

I don't understand the question. Why can't you run the fridge?

The only symbols I'm familar with for AU, is the country of Australia or the chemical symbol for gold. I'm sure there are many more.

Take a look at the charging chart on the bottom of this link.

Definitely you should never count on your truck to fully charge your batteries.  But it should help maintain the general health of a fully charged battery while on the road and especially when the Refer is running drawing the 12v power.

http://www.progressivedyn.com/prod_details/charge_wizard.html

I also like this chart. I use it in conjunction with my battery meter that I keep plugged into the 12v outlet.

http://www.ccis.com/home/mnemeth/12volt/voltchart1.gif

Battery meter:  (Walmart has it in the marine section too)

http://www.rvwholesalers.com/catalog/12v-digital-meter-19-0350.html

To make mine charge "RIGHT", I added a larger cable from the battery to the rear of the truck and used a quick coupler (like they use in wreckers for jumper cables) mounted on the rear and the plug on the trailer to the batteries.  I used 4ga on the truck and trailer along with a breaker just incase.

This works much better that the little 14ga wire in the 7 way plugs and now I can use this on mydump trailer and power jack with no power drop or slow running motors.

Very interesting HTB. 

Where did you run the 4awg wire to in your truck? 

I wonder if this would be a good use of an upfitter switch?

Can you post a link to a picture of the coupler (if you can) 

I would like to do that for my dump trailer.

I run 1 cable all the way to the battery on the truck and a short cable to ground to the frame on the rear of the truck.

Same on the trailers, 1 to the batteries and a shorter cable to a place out of the way on the frame for a good ground.  Just make sure you have enough slack on the trailer side for turns (I used cable ties to run along with my 7 way trailer plug).

I will get some pictures after lunch to post for you. 

Maybe a little over kill, but works great!

One picture shows how I mounted one plug to the rear of my truck, the other I tried to get a close up of the plug that is on the trailer.

Northern Tool did carry some ends like this in the auto/truck section with the jumper cables.

I got a single battery that gets it recharge, from the hot all the time lead off the truck. Truck alternator will rechage the battery if you drive a long distance otherwise it will need to be touched up with a regular battery charger, if it has been pulled way down. With a dual battery set up you would have to drive all the way across country for the truck to recharge them through a 14 gauge wire....

Mine charges from the same hot wire in the 7 way plug also but when puttting a load from an electric jack or electric motor from a dump trailer that small 14ga wire gets HOT and I have low power and a slow working motor.

With this deal I use on my trailer, I have good power all the time which I think would be better on the motors I am working with.  The 4ga maybe an over kill, but I had a roll left from my wrecker so it was FREE.

That's the same type plug we used on the "drag car" many years ago.... Won't fit but one way.

Yeap, that way if the better half has to hook up she will not have to call and say which way does this plug go, only plugs in one way.....

No more than you do with the regular trailer plug left plugged in...

But I also have a generator I use when we camp and when I park for the week or weekend, I unplug both plugs from the truck and plug into shore power....

I think Dodge is the only live with key off 7 way. 

I also unplug the truck when camping.