Truck to camper wiring questions

[jonwegs]

I am new to the forum and owning a 2003 Lance 815. Vehicle is 1992 F-250 7.3 IDI. Also inexperienced with electrical systems.

My plan for the setup is almost always dry camping. So I am really wanting to get the battery charging system dialed in. I have already bought Lance's unique truck side male plug which I quickly learned I needed. My model does not have a built in battery isolator/separator.

I hoped I could wire the lance plug directly into my 7 pin in the bed of my truck, but the trailer wiring has smaller than 8 gauge wire for the power wire and ground wire. I tried this and the running lights work, but I now know the smaller gauge hot wire and ground won't charge the camper battery.

What do I need to do to successfully and safely wire my camper to the power generated when the engine is running?

Some say wire 8 gauge or bigger directly from the truck battery via an isolator, some say from the alternator via an isolator. While others say just wire it directly to the windshield wiper motor.

I will also have a solar panel (being shipped now), so ideally this will not be the only way my camper battery gets charged.

Any advice, links, or previous posts I didn't find would be greatly appreciated. And apologies for my ignorance on what seems like such common knowledge info for experienced folks.

[Kayteg1]

jonwegs wrote:
Lance's wiring harness has the positive and negative wires as 8 gauge, and Lance specifically said don't use charge cables smaller than 8 gauge.

You should read whole story.
Lance made #8 wires with special plug for refrigerator running of truck alternator.
You specifically said that you are not planning to do that ????
Mine Lance had the plug converted to standard 7-pins and I know the PO of my Lance wasn't the only one who did not like the hassle, when #8 wire is way more than necessary to recharge single battery Lance has. .
You are assuming a lot, while not checking much. So is your truck factory wire ignition-operated or not?

[Grit_dog]

Kayteg is generally correct in that you don't want to charge with an extraordinary amount of amperage but if you have camper batteries paralleled to the truck batteries, with heavy wire, the batteries will attempt to equalize to the weakest one(s) and the alternator will take care of it.
If you want a set it and forget it setup, I'd suggest coming off a truck battery with a voltage sensing isolator like a Blue Seas ACR. When it senses charging voltage (truck running) it will latch and charge the camper. When voltage drops below 12.5V ( like shortly after truck is turned off)or something like that, it will disconnect from the truck batteries. Hook it up once and get full charging power from the alternator when the truck is running and auto disconnect.
It can work in reverse if the solar puts out enough voltage too. Idk what voltage solar charges at.

[jonwegs]

Kayteg1 wrote:
BUT WAIT !
There is more 😉
Running bigger than factory #10 wire to camper would make sense when you have 6-battery bank, but rule of thumb says you should not charge the batteries with current bigger than 10% of their capacity.
So 100 amp-hr battery should not be flooded with more than 10 amps.
Ford is the only brand that is having trailer 30 amp charging wire operated by ignition, so check if yours might already have it.
Bigger wire with bigger connectors might make sense when you use 12V for fridge, but sounds that you might already have all you need?

I definitely don't need tons of power for what I am trying to do, but Lance's wiring harness has the positive and negative wires as 8 gauge, and Lance specifically said don't use charge cables smaller than 8 gauge. More than likely, I will just match the Lance plug and run 8 gauge wires for charging.

My truck being a 92', I'm not sure what applies for stock wiring, but it looks like a lot is going on from the previous owner's 5th wheel setup. But definitely no big charge wires. Smaller than 8 guage for sure. I'd post photos but apparently I'm just not seeing how to do that with this format.

As for weather to run the charge wires through an isolator, or the constant duty solenoid AnEv recommended, I don't know. I'm still not super clear how they are different, but I can always keep reading.

[Camper_Jeff___K]

jonwegs wrote:
Thank you everyone for the info. I have some reading to do now. As for your question Brad, my fridge has the 12v option but I plan to mainly run it off propane.

Based on the info I have thus far, it sounds like I need to buy 20+ feet of 8 gauge or bigger wire, possibly a constant duty solenoid or a battery isolator (still need to read a bunch on those to understand which I need). I have seen some folks take the positive and negative wires out of the Lance harness and wire those up to the battery, while just using my existing 7 pin in the truck bed for the running lights. This makes sense to me, does anyone see any issues with doing that?

I rewired my TC 6 pin to 7 pin. I still have and use the charge wire of the 7 pin but the real charging power comes from the new 4 gauge connection. Earlier post.

Video Example Of 4 Gauge Wire And 7 Pin Plug Connections.

[Kayteg1]

BUT WAIT !
There is more 😉
Running bigger than factory #10 wire to camper would make sense when you have 6-battery bank, but rule of thumb says you should not charge the batteries with current bigger than 10% of their capacity.
So 100 amp-hr battery should not be flooded with more than 10 amps.
Ford is the only brand that is having trailer 30 amp charging wire operated by ignition, so check if yours might already have it.
Bigger wire with bigger connectors might make sense when you use 12V for fridge, but sounds that you might already have all you need?

[jonwegs]

Thank you everyone for the info. I have some reading to do now. As for your question Brad, my fridge has the 12v option but I plan to mainly run it off propane.

Based on the info I have thus far, it sounds like I need to buy 20+ feet of 8 gauge or bigger wire, possibly a constant duty solenoid or a battery isolator (still need to read a bunch on those to understand which I need). I have seen some folks take the positive and negative wires out of the Lance harness and wire those up to the battery, while just using my existing 7 pin in the truck bed for the running lights. This makes sense to me, does anyone see any issues with doing that?

[jonwegs]

trail-explorer wrote:

jonwegs wrote:
While others say just wire it directly to the windshield wiper motor.

That's the most bizarreway of wiring in a charge circuit that I've ever heard.

To the wiper motor is NOT the right way to do it.

Unfortunately Bob, I heard that from the service mechanic at the only RV dealer and service center here in Durango, CO. I had wondered about that, but now I know its best probably not to have any work done there.

[Camper_Jeff___K]

d3500ram wrote:

Camper_Jeff_&_Kelli wrote:
Here is how I did my 4 gauge wire and solenoid installation. There are several other examples in the Truck Camper University sticky section.
4 Gauge Charge Wire

Jeff- I think that is the single longest thread I have ever scrolled!
Nice job and documentation!

Glad you liked it. Spent a few hundred bucks for materials and tooling. Add to that the time figuring out what to do, how to do it, and then the time to do it. By far my most rewarding TC improvement project. Take care,,,

[trail-explorer]

jonwegs wrote:
While others say just wire it directly to the windshield wiper motor.

That's the most bizarreway of wiring in a charge circuit that I've ever heard.

To the wiper motor is NOT the right way to do it.

[d3500ram]

Camper_Jeff_&_Kelli wrote:
Here is how I did my 4 gauge wire and solenoid installation. There are several other examples in the Truck Camper University sticky section.
4 Gauge Charge Wire

Jeff- I think that is the single longest thread I have ever scrolled!
Nice job and documentation!

[Hemi_Joel]

It is important to have very little voltage drop between the camper batteries and the truck batteries. THe wires need to be big and the connections very good. Because the trucks voltage regulator senses battery voltage, and adjusts the alternators output accordingly. When the battery voltage is low, the regulator cranks up the alternators output to charge it. The truck battery is right next to the alternator, so the voltage regulator has a tendency to sense only the truck battery voltage, reducing the rate of charge below what is needed to charge the camper batts. A better connection from the camper batteries to the truck battery causes the regulator to sense their voltage and increase the alternator output.

[Camper_Jeff___K]

Here is how I did my 4 gauge wire and solenoid installation. There are several other examples in the Truck Camper University sticky section.
4 Gauge Charge Wire

[cewillis]

AnEv942 wrote:
Search constant duty solenoid will bring up a few old threads, also a couple in the TCU sticky. Simplest and effective is using constant duty solenoid-triggered by ign hot.

Right -- plus heavy gauge wire (if you want a full charge). I use 2g -- never a problem. (also supplies winch power)

[BradW]

jonwegs wrote:
I tried this and the running lights work, but I now know the smaller gauge hot wire and ground won't charge the camper battery.

There should be enough juice at the 7-way plug to charge your camper battery. It may not charge it as fast as if you had it wired directly with an 8 gage wire, but it should be enough for normal charging.

The problem comes in if you are pulling above "normal" amps. In particular if your are trying to running a 12V frig. For something like that, you will need the 8 gage wire.

Do you have a 12V frig?

Brad

[Hemi_Joel]

I use a 250 amp blade switch, mounted on the bolt that tightens the positive battery terminal on the truck. Then a 10 gauge wire to a lift gate connector, wired direct to the camper batteries. with a pair of 10 gauge wires for the ground. THe 10 gauge wire seems to be enuff, but I'm sure 8 or 4 g would be better. I only open the switch to protect the truck battery when I am going to be dry camping in one spot for more than 2 or 3 days without much sun to run the solar panels. What I like about the blade switch is that it is simple to install, reliable, I can take advantage of the truck battery capacity, and there is no measurable voltage drop. What I don't like is I have to open the hood and do it. I use a combo deepcycle/starting battery in the truck and a pair of 6v golf cart batts in the camper with 200w solar.
I have never ran the batteries down enuff that the truck did not start, but I figure if I did, it should still start the generator to charge it back up.

https://www.awdirect.com/knife-blade-battery-switches-for-side-terminal-batteries/battery-tools-accessories/