Camper Backwashing Power Into Vehicle

[jentrxm]

We just bought our first camper ever, and an issue popped up that I'm hoping you all can shed some light on (Google failed me).

We bought a pull behind camper at a Camping World location and had them install a brake controller in our 2007 Jeep Grand Cherokee tow vehicle.

We very quickly discovered that the radio and 12v outlet in the Jeep were running even with the ignition off and the keys in my hand. A CW tech disconnected the car battery to unhook the brake controller wires, but after he unhooked the battery the power was still on inside the vehicle.

We figured out that power was flowing backwards through the 7 pin connector and it was the camper battery powering everything inside the Jeep.

The CW tech claimed the problem must be with the Jeep, but I don't trust them.

Has anyone else ever seen a problem like this? I'm wondering if the trailer is wired wrong.

[opnspaces]

Not normal at all, the trailer charging line is wired incorrectly.

There is no way the 12v from the trailer battery should be powering the ignition circuit of the Jeep. My guess is the issue existed before the brake controller was installed. You just discovered it now because the trailer has a battery in it. What happens if you have the key out and the radio playing and then unplug the brake controller? If the radio goes out the tech did something wrong. If the radio keeps playing then the tech did not cause the issue.

[Dtank]

CA Traveler wrote:



Don't let the same tech near your equipment.

Now hang on there....he's a *CAMPING WORLD* Tech...:B

:R

[PaulJ2]

You have a wiring error. Someone probably thought it would be cool to just connect the power to the trailer through the jeep ignition circuit so it would automaticly cut off with the key. Would not have to by one of those expensive relay systems etc. Previous owner probably pulled some kind of trailer with no battery in it.

[ajriding]

My GM vehicle came with "factory tow package" yet was half-arced crimp spliced together from the rear light wiring to feed 4 of the 7 wires into the 7-pin. Don't rely on that, it could have been the dealer that "factory" installed the trailer wiring.

Your Jeep wire is connected to the ignition side of things, no doubt.
You need to re-do this for sure.
You are not getting very good current flow to the trailer.
The wire should come from the alternator and go as directly to the 7-pin plug as possible with a heavy gauge wire, one wire, since you will have ground from the chassis.

Jeep people have it come off the ignition side so that when key is off then you will not run down your vehicle battery.
I suggest using a relay switch and wiring straight off the alternator (or battery, or starter 12v+ post) yourself.
The relay can be connected to the ignition (maybe that same radio wire/ same wire that is feeding the 7-pin charge wire currently).

If too advanced then have a mechanic do it.

Honestly, I do not know exactly how a "factory" wiring would look. I have always used the relay method so I can control it via switch. With solar I never really need to charge from the TV anyway.

edit: relay about $7-$14 and a switch $2-3, a relay harness maybe around $10, but you dont have to have one.
I bought a5 pack like this https://www.amazon.com/Pack-EPAuto-Relay-Harness-Bosch/dp/B017VDI0GY/ref=sr_1_3?keywords=relay+harne... and have multiple trailer things on it
including:
trailer 12 volt Heavy Duty Relay which powers trailer charging, reverse lights and running lights.
Feeding off the relay are:
trailer charge
trailer reverse light
trailer running lights
note, brake light is left alone.
By having a separate power source for the trailer there is no chance to trip or blow a fuse on the TV or burn out wiring from too many lights on a trailer…

and for more fun:
truck reverse light
truck DRL

[jentrxm]

The 7 pin harness is factory as far as I know. I am not the original owner of the Jeep. CW only installed the brake controller.

I'm a little paranoid about them, though, because when I opened my trunk I found the power wire to my subwoofer completely torn or of the amplifier and I don't think that would have magically happened on its own.

[ajriding]

second on not using diode for voltage drop reason.

Not normal at all!

Trailer brakes only send out 2 volts, and a max of 6 when full brake is applied. Not enough to run anything in the TV. trailer brakes are completely separate system and olny connected to trailer battery when the emergency pin is pulled. Major issues if the brake is at play. maybe installer puled 12v power from the TV to run to the brake controller and somehow crossed wires, if so then start over from scratch.

More likely your trailer batt is powering up your ignition wiring, instead of your TV battery wiring as is common. This would mean the power to the trailer is coming off an ignition wire (wire that has power only when the key is on) that is connected to the radio, so maybe is on the same circuit,fuse as the radio.
Someone in this case pulled power from the wrong place, but seems like this situation would blow the radio circuit fuse if the trailer battery is low enough to pull a strong flow of amps.

The radio will kill batteries over time. Nuisance to have to unplug all the time. You dont want the TV battery drained from using your camper either.

[LittleBill]

i took a brief look in alldata, his truck is a bit complicated, appears to use can bus for the radio switched circuit, truck also has a factory tow option, not sure if his has it.

but agreed there is a issue.

[CA_Traveler]

I would not use a diode due the 0.6V drop in addition to the wiring loss. Newer cars often require a reasonable charge line due to equipment that remains on like computers and navigation. Check the towed battery voltage when setup for towing and see if it will at least maintain the battery vs the battery draining. It's a long run from the Jeep battery to the towed battery and the wiring may/not be adequate.

Listen to Doug - I wondered about your 07 Jeep charge circuit but have no experience with that car. But it doesn't surprise me that the charge circuit should be off when the engine is off.

[dougrainer]

1. 2007 Jeep
2. If all they did was install a Brake Control, there is more to this story
3. Are you the original owner of the Jeep? If not, a previous owner may have miswired the tow wiring system
4. The 7 pin connector has a HOT(battery Positive charge wire). THAT wire is supposed to be DEAD until the engine is on OR it is connected directly to the Jeep battery bypassing your Ignition switch. Some older vehicles that continuous HOT will drain a Vehicle battery if you leave the trailer connected when not driving.
5. When the Jeep Key is OFF and you connect the RV, you have suppled 12 volts positive TO the Jeep charge circuit. That then supplies 12 volts from the rear of the Jeep to the front area where obviously it is powering the IGNITION (Key ON) side of the Jeep Dash. NOT supposed to happen
6. Just installing a brake control should not have caused your problem. BUT, if they also wired the Charge line to the rear of your Jeep and installed the 7 way tow plug on your Jeep, then that is CW's problem. The connected the Charge wire to the wrong area of the Jeep wiring harness, IF THEY DID THAT wiring.
7. Brake control has 4 wires---1. HOT from the Jeep fuse panel 2. Ground(negative). 3. wire connected to the COLD side of Brake pedal light switch. 4. Wire running to rear 7 way trailer connector. NONE of these would power the Ignition side of your Jeep. If done correctly.
8. AS stated, If you are not the original owner of the Jeep, then the problem may be that. Doug

[cavie]

jentrxm wrote:
Little Bill, yes. It keeps playing with the switch in the off position and the keys removed from the ignition. I didn't think that could possibly be normal either. When you unplug the 7 pin it stops instantly.

GM does that until you open the door.Then the radio will shut off.

[LittleBill]

jentrxm wrote:
Little Bill, yes. It keeps playing with the switch in the off position and the keys removed from the ignition. I didn't think that could possibly be normal either. When you unplug the 7 pin it stops instantly.

as far as i am concerned, it has a issue, the vehicle should operate identically with or without the 7 pin connected. circuits in the jeep should not be powering up, just because you connected the 7pin trailer harness.

take the vehicle to some one else, and have it checked. i personally believe you have a issue.

[bdpreece]

CA Traveler wrote:

jentrxm wrote:
Thanks everyone! Glad to know it's normal and not some crazy wiring issue.

Normal but not desirable unless you want to unplug/plug all the time.

One simple solution is a relay in the Jeep charge line that is activated by the ignition. Don't let the same tech near your equipment.

An even simpler solution is to put a diode in the line. Current will then only flow one direction.

[jentrxm]

Little Bill, yes. It keeps playing with the switch in the off position and the keys removed from the ignition. I didn't think that could possibly be normal either. When you unplug the 7 pin it stops instantly.

[LittleBill]

although most are saying normal, radio's don't generally have power without the ignition switched on, they have a constant power feed as well, but thats just for memory settings, are you saying you can actually play the radio without the vehicle in accessory mode? if you unplug the trailer does it do the same thing?