How to wire Camper Battery to truck ?????

[Rbertalotto]

This might be a long question.....

I have a pickup trucl with a small Palomino camper. The camper has a battery, the truck has a battery.

The connector on the camper is a four pin, trailer type connector.

One wire is ground
One wire is clearance lights
one wire is 12V to the refrigerator
the last wire is to the camper battery

none of these wires is bigger than 16 ga.

I understand the ground and clearance lights......

Question #1: What is the 12V wire to the refrigerator for. The refrigerator has gas, 120V and a 12V connection. But it says only "gas" and "12V" on the control knob. Will the refrigerator run on this relatively small 12V wire? Why does it have a 120V connection that is wired to shore power?

Question #2: Is that 16ga wire large enough to charge the camper battery?

Question #3: What is the best way to automatically disconnect the truck battery from the camper when the truck's engine is off?
I see a device called an "Intellitec" latching relay. But this device requires me to push a button to connect or disconnect. I might as well put a manual switch in the line.
Can I use a simple 30A automotive type 12V relay (little black square jobbers) that is activated and connected when truck power is applied to it and disconnected when power is off?

Any help will be hugely appreciated........

THANKS!

 

[brian90744]

the 4 wires are Left turn/brake, Right turn?brake, lights/marker, ground. show pic of camper would help.

 

[Rbertalotto]

the 4 wires are Left turn/brake, Right turn?brake, lights/marker, ground. show pic of camper would help.

There are no indicator or tail lights on the camper. The owners manual calls out the wires as I posted. This I'm positive of.

 

[brian90744]

Roy.
I guess you follow the owner manual. yes you may have a 3 way refrig 12V,110V. LPG. are the wire gauge (16G) large enough for charging the camper battery=NO, At your truck trailer, should be a 7 pin/spade outlet, one of these wire is OK=12V chargeing=Red - Left turn
Brown - Right turn
Green - Clearance lights
White - 12V(-) ground
Black - 12V(+) hot
Yellow - Back up
Blue - not used, brake feed
thanks=brian

 

[Rbertalotto]

Yes, my seven pin at the rear of the truck is wired as you say, including the brake wire, which is active with a brake controller for my motorcycle trailer.

But the 12V battery feed wire for this 7 pin plug isn't much bigger than 10g.

Dometic RM2310 refrigerator. It appears to be a 2-way (12V / Gas) as it only has a two position knob on the front (12V -Gas). But when I look at the back through the service door, it is wired to the campers 120V system..........

The owners manual says if it was a 3-Way it would have a position labeled "ELEC" on the selector knob. Which this refrigerator does not have. ?????

 

[docdave]

Does this refrigerator run on 12v when the camper is plugged in, via an inverter?

 

[dwh]

Question #1: What is the 12V wire to the refrigerator for. The refrigerator has gas, 120V and a 12V connection. But it says only "gas" and "12V" on the control knob. Will the refrigerator run on this relatively small 12V wire? Why does it have a 120V connection that is wired to shore power?

The manual does say that there should be a 12v option on the control knob - IF equipped for 12v operation. My guess is that you have a 2-way (gas/120v) which is NOT equipped for 12v operation, and that the 12v wire to the fridge is purely to power the thermostat. If you were operating on gas and had no shore power - how else would the unit have power for the t-stat?

In that case, then the dinky lil' 12v wire is fine because it only carries enough current for the t-stat. It probably also needs to be a constant supply, since if it was switched off the t-stat couldn't work and the fridge wouldn't work even on gas.

Question #2: Is that 16ga wire large enough to charge the camper battery?

It depends.

Theoretically...yes, it could charge the battery as long as the charge current did not exceed the ampacity rating of the wire. It might take a lot longer to bring the battery up to full charge - due to voltage drop - but it should...maybe...eventually get the battery to full charge voltage.

Question #3: What is the best way to automatically disconnect the truck battery from the camper when the truck's engine is off?
I see a device called an "Intellitec" latching relay. But this device requires me to push a button to connect or disconnect. I might as well put a manual switch in the line.
Can I use a simple 30A automotive type 12V relay (little black square jobbers) that is activated and connected when truck power is applied to it and disconnected when power is off?

Yes, you could use a typical (Bosch type) 30a relay instead of the Intellitec - as long as the charge current doesn't exceed 30a. Which it probably doesn't, seeing as how the charge wire you have now is so small.

Better would be to yank the Intellitec and rig this setup:

http://www.expeditionportal.com/for...-dual-battery-setup-for-50?highlight=isolator

 

[dwh]

BTW, for those who don't know, the Intellitec is a dumb solenoid relay that latches in the open or closed position - so it only consumes power momentarily whenever the switch is set to on or off:

http://www.pacificrvparts.com/ProductDetail.asp?PID=41968&RP=Default

 

[Rbertalotto]

So I'm out here in the rain doing some wiring! I found out a few things. The wire feeding the camper battery is 12 gauge. And the wire going to the refrigerator is 12 gauge. I replace the wire for the camper battery with 8 gauge. I'm going to use a simple relay to turn the truck battery on an off. West Marine has 1 rated at 100 amps.

To answer the question about how the refrigerator runs. I've yet to get it running. It does not run on just 120 volts. Maybe it needs that 12v hooked up also.
But I checked again And the knob on the front of the refrigerator Simply says GAS or 12v.
Stay tuned

 

[dwh]

Yea, weird. The manual doesn't mention gas or 12v, only gas, elec or 12v. Maybe it's really a gas/elec with the wrong label?

And yea, I would bet that the thing requires 12v to power the thermostat no matter what, which may be why it isn't working.

Also, RV type fridges are notorious for having the control boards fail. My little Norcold 323 doesn't have a thermostat or a control board, so that's a non-issue for me. Dinosaur Electronics makes hot-rod replacement control boards for a bunch of RV appliances:

http://www.dinosaurelectronics.com/


EDIT: Oh, and just FYI - My Norcold 323 is the smallest they make, and it draws 12 amps running on 12v. That's a LOT and will take down a battery in a hurry. So really, an ammonia absorption RV fridge should only be run on 12v is if the engine is running. But switching back and forth is a PITA and I just never run mine on 12v at all.

 

[Rbertalotto]

I solved the 12V / 120V refrigerator issue.

I turned the knob much harder that I previously had and sure enough there was a 120V position. Seems the knob was stuck.

So now I have everything hooked up, but the refrigerator will not turn on. I'll have to do more investigationg this week to see if I can resolve this issue.

Thanks for all your help!