Greetings,

We bought a camper around 5 months ago. As part of the final negotiations we asked at the time if the RV dealer could wire our 2008 unlimited sahara with the required wiring harness which they did. I didn't see the actual install and I am not sure if they used mopar parts for this but I assume not. However, it looked pretty smooth and seamless.

On our last trip we arived to the campsite realizing that the battery was dead. I borrowed a battery from the camp next to us and managed to get the automatic winch up. (We purchased a 2300 pound popup trailer)

When we got back home from that trip I took the camper back to the dealer to fix several items including figuring out what was wrong with the battery and why it wasn't charging.

I am starting to think that they just installed a 7-pin to a 4-pin to cut time? Does this sound about right? Do you have to run a wire all the way to the battery to get it to charge the battery on my camper on a 2008 Sahara? Isn't that the point of the 7pin? What's the point of starting your refrigerator the night before then if it will kill the battery?

Another final issue I couldn't understand was the fact that we tried to use 110 volt at the campsite and the battery still didn't charge? This leads be to believe that something is wrong there as well?

Ideas?

 

It has been my experience that the 7 pin connectors installed by dealerships only add trailer brakes to the "regular" circuits in a 4 pin connector.

There are room for other circuits within the 7 pin connector but I have never seen a "stock" install use them. Pretty much a 4 pin connected to the back of a 7 way connector and a blue brake control wire running to the controller in the cab.

However... an RV dealership should have installed the charging circuit, especially if it was for a camper you bought from them.

I believe it's the number 4 pin that should have 12 volts on it. I think the wire is usually black. I like it to only have power when the vehicle is running ( or key is on ) to prevent killing the tow vehicles battery when you are camping but still connected to the tow vehicle.

The middle aux circuit can be used for backup lights but I have never personally seen anyone use it for anything.

 

Even if they did wire the outlet correctly I wouldn't rely on it to charge the battery since the size of the wire is very small and it will not charge the battery much at all.

The way we do it is to plug the trailer into 110V from the house for a day or so before we leave and run the fridge off of that then switch it to propane during the trip and while we are camping or if there are 110V plugins switch it back to power. Your trailer battery should be charging when you are plugged into 110V and if not there is something wrong with the wiring.

 

the factory harness, if they used it has a black and a white wire which starts at the battery , goes across the firewall to the driver's side then down the frame. The black wire is 12 volt . Easy to check the back side of the plug , count the # of wires, then test with a test light to see if you have constant power on the rh top pin.

 

if your battery didn't charge with the 110 then the problem is probably your converter in the trailer. I would first take a 12 tester and see if you have 12 volt on the 7 pin. there are many diagrams on the net which will tell you which pin should have the 12 volt. Make sure you try it with the key turned to acces. and without. If you don't have power, your rv dealer didn't wire it right.

Second, the 12 volt usually comes off of the 7 pin connector, to the trailer converter, then back to the battery. I've had many trailers and with all of the bouncing that trailers do sometimes the wires in the converts can come loose. check your connections there.

If this doesn't work, go back to your rv dealer and raise hell!!!

 

Don't think you would ever get a decent charge out of the 7 pin - I never did - your best bet is to plug it in at home to get a full charge.

 

Thanks for all the replies. To make a long story short, they just installed a 7 to 4 pin install. However, more importantly, there was something wrong with the charge/fuse that charged the battery when plugged to 110V.

 

Yes, they need to run a power source to the 7 pin connector specifically for charging the battery. I have a similar set on with my TJ for my boat trailer (has a battery for the electric over hydraulic brakes) and I wired everything up myself, doing a 4 pin to 7 pin conversion. I ran the wire directly to my battery and everything works fine.