Wiring Camper

[JLehman]

Hi, Just finished hookin up lights and power on camper, lights are good, my friend who worked at a Dodge dealer helped me and hooked the power fior charging the camper battery right off the alternator. Is this a good idea?? Check engine lite came on and threw code 1757 something about governor pressure or lack of. Any ideas>>?? thanks

 

[PKnoerzer]

If you have the tow package, you already have a charge circuit to tap into.

 

[tandersen]

You need to come off of one of the batteries through a 40 amp circuit breaker with at least 8 gauge wire back to the camper connection. It's my understanding the wiring in the tow package harness is to small.

 

[fkovalski]

... It's my understanding the wiring in the tow package harness is to small.

Yes, I agree it is too small... however...

... . through a 40 amp circuit breaker with at least 8 gauge wire back to the camper connection. ... .

Is this too high of a current relay? I am going wth 30A (fused) and 10G wire. Too high of a relay may pull too much current to not trip the fuse (if in fact you are using a same rated fuse) when overload protection is needed.



I was even looking into an internal charge sensing relay (isolator) are not so reliable in the long run, but have heard that the relay is the better way to go.

 

[tandersen]

fkovalski you are right about the relay. I forgot about that as my Lance camper has it built into the camper electrics. The relay does work well, I've used it on another camper. The circuit breaker and wire size are a Lance recommendation.

 

[fkovalski]

... hooked the power for charging the camper battery right off the alternator. Is this a good idea??

In theory, is this not the same as connecting right to the battery? I have heard of folks tapping right to the battery with no type of isolator or relay without trouble except for possible battery drainage- see next quote.

If you have the tow package, you already have a charge circuit to tap into.

I believe that this cicuit to which you refer is NOT a 'key- off' line. If you have no type of discconect, then possible vehicle battery drain is possible.

... . The circuit breaker and wire size are a Lance recommendation.

The Lance's must have many more electrical goodies to require more current.

 

[tandersen]

fkovalski I don't know if it's the same as hooking to the battery in theory. It must not be because I have no problems being connected the battery. I don't know if it's a "key-off " line, I have never checked mine as I am not using it. You could be right about the Lance requirements. I had an older Ford that was wired to alternator and then through an isolator to the truck and camper batteries. The connection at the alternator failed while I was on a road trip because of the poor quality of the wiring done by an rv store. I think it is a better idea to go from the battery. Anybody else with thoughts on this?

 

[JLehman]

Thanks for the replys guys, but my reason for going from the alternator instead of the battery is that i don't want to go to start my truck out in the boonies and not have the juice to crank it cause i dont have a gen for the camper battery. the fuse or circuit breaker is a great idea for sure, i ran 10 gauge wire back to the plug i installed in the bed. Seems to work fine so far just got back from a 3 day trip. So far so good.

 

[tandersen]

JLehman you are not isolated from your starting batteries the way you are wired. You need an isolator or better still a starter type relay.

 

[tandersen]

Here's some stuff to look at.



http://www.smithae.com/surepower.html





http://www.geocities.com/harald_nancy/isolator.htm

 

[DBond]

Yes, I agree it is too small... however...



Is this too high of a current relay? I am going wth 30A (fused) and 10G wire. Too high of a relay may pull too much current to not trip the fuse (if in fact you are using a same rated fuse) when overload protection is needed.

The OEM wire is 14 AWG, wimpy, and there is no OEM switching to this power, it's always on.

You can't have too high of a current rating on a relay (though overkill could be impractical). Did you mean too high of a Fuse/Circuit breaker?



Per ANSI/RVIA 12V standard, Overcurrent protection;

10 AWG 30A. if no more than 3 wires per harness 40A with 90C insulation, 50 with 105C insulation.

8 AWG 40A. if no more than 3 wires per harness 55A with 90C insulation, 70 with 105C insulation.



That said, you need to have the fuse/circuit breaker set to the weakest link in the truck-cable-camper chain. The cable from the truck to the camper is likely to be 10awg (unless you have setup a seperate power line pair) so 30A probably what it should be.

 

[DBond]

JLehman you are not isolated from your starting batteries the way you are wired. You need an isolator or better still a starter type relay.

The starter relays I have seen are only specified for intermittent duty, so the coil could overheat and fry when on continously. Where do you find continous duty ones?

 

[fkovalski]

... Did you mean too high of a Fuse/Circuit breaker?...

Yes,... . thanks for the clarrification.

 

[JLehman]

tandersen, thanks, now that u mention it i do believe your rite lol, sometimes i'm really brain dead

 

[fkovalski]

What is anyone's opinion on charge sensing isolator such as-->HELLRAORING TECHNOLOGIES.



I was leaning towards this type of isolator where the internal 'electrical guts' would sense the alternator charging voltage and switch internally on/off based on the voltage it sensed. It sounded good especially since it is an 'in- line' install. They cost about $150.

 

[WestT]

I installed a hellroaring isolator on my rig. I mounted it on top of the fuse box in front of the left battery.

It has been working fine.

I ran a 10 g or 8 g wire to the camper battery.

 

[tandersen]

The starter relays I have seen are only specified for intermittent duty, so the coil could overheat and fry when on continously. Where do you find continous duty ones?

DBond I bought one at an rv place.

 

[Prairie Dog]

DBond I bought one at an rv place.

NAPA sells one too, just make sure you ask for the all-metal 100% duty cycle part ~ about $25.



Scotty